Ubisoft launcher installed, but can not start

Hello,

I use CachyOS and installed Lutris via Octopi (CachyOS package manager). The version is 0.5.19-6.

First, I set up Steam and everything works fine. Now I wanted to install Ubisoft Connect, which also worked. But as soon as I try to start it, I get an error. See screenshot.

I have already run lutris --submit-issue. A JSON file has been generated. How can I deploy it or upload it here?

Here is the lutris -d output:

lutris -d
INFO     2025-08-25 10:31:49,476 [application.do_command_line:478]:Starting Lutris 0.5.19
INFO     2025-08-25 10:31:49,495 [startup.run_all_checks:120]:"card1" is AMD Radeon Graphics (1002:13c0 1849:364e amdgpu) Driver None
INFO     2025-08-25 10:31:49,602 [startup.run_all_checks:120]:"card0" is NVIDIA GeForce RTX 5090 (10de:2b85 1462:5306 nvidia) Driver 580.76.05
DEBUG    2025-08-25 10:31:49,648 [xrandr.get_resolutions:91]:Retrieving resolution list
DEBUG    2025-08-25 10:31:49,649 [xrandr._get_vidmodes:18]:Retrieving 40 video modes from XrandR
DEBUG    2025-08-25 10:31:49,666 [path_cache._update_missing_games:114]:Checking for missing games
DEBUG    2025-08-25 10:31:49,677 [api.check_stale_runtime_versions:52]:Modified at Mo 25 Aug 2025 10:17:39 , will update after Mo 25 Aug 2025 16:17:39 
DEBUG    2025-08-25 10:31:49,677 [lutriswindow.create_runtime_updater_cb:1384]:Runtime up to date
DEBUG    2025-08-25 10:31:50,667 [http._request:88]:POST https://lutris.net/api/users/library?since=1756110306
DEBUG    2025-08-25 10:32:05,835 [xrandr.get_outputs:26]:Retrieving display outputs
DEBUG    2025-08-25 10:32:05,836 [xrandr._get_vidmodes:18]:Retrieving 40 video modes from XrandR
Started initial process 7867 from gamemoderun mangohud /home/sascha/.local/share/lutris/runners/wine/wine-ge-8-26-x86_64/bin/wine /home/sascha/Games/ubisoft-connect/drive_c/Program Files (x86)/Ubisoft/Ubisoft Game Launcher/UbisoftConnect.exe
Start monitoring process.
gamemodeauto: 
gamemodeauto: 
ERROR: ld.so: object '/usr/$LIB/mangohud/libMangoHud_shim.so' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored.
gamemodeauto: 
ERROR: ld.so: object '/usr/$LIB/mangohud/libMangoHud_shim.so' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored.
gamemodeauto: 
fsync: up and running.
wine: RLIMIT_NICE is <= 20, unable to use setpriority safely
ERROR: ld.so: object '/usr/$LIB/mangohud/libMangoHud_shim.so' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored.
Initial process has exited (return code: 0)
[2025-08-25 10:32:06.611] [MANGOHUD] [info] [blacklist.cpp:75] process 'explorer.exe' is blacklisted in MangoHud
[2025-08-25 10:32:06.778] [MANGOHUD] [info] [blacklist.cpp:75] process 'tabtip.exe' is blacklisted in MangoHud
ERROR: ld.so: object '/usr/$LIB/mangohud/libMangoHud_shim.so' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored.
ERROR: ld.so: object '/usr/$LIB/mangohud/libMangoHud_shim.so' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored.
ERROR: ld.so: object '/usr/$LIB/mangohud/libMangoHud_shim.so' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored.
ERROR: ld.so: object '/usr/$LIB/mangohud/libMangoHud_shim.so' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored.
ERROR: ld.so: object '/usr/$LIB/mangohud/libMangoHud_shim.so' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored.
ERROR: ld.so: object '/usr/$LIB/mangohud/libMangoHud_shim.so' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored.
Monitored process exited.
Exit with return code 0
DEBUG    2025-08-25 10:32:13,118 [monitored_command.on_stop:232]:Process 7860 has terminated with code 0
DEBUG    2025-08-25 10:32:13,842 [game.beat:910]:Game thread stopped
WARNING  2025-08-25 10:32:13,842 [game.on_game_quit:948]:Game still running (state: running)
INFO     2025-08-25 10:32:13,842 [game.stop:921]:Stopping Ubisoft Connect (wine)
DEBUG    2025-08-25 10:32:13,842 [game.stop_game:877]:Ubisoft Connect (wine) has run for 8 seconds
DEBUG    2025-08-25 10:32:13,843 [game.stop_game:889]:Playtime: Less than a minute
DEBUG    2025-08-25 10:32:13,843 [game.on_game_quit:966]:Ubisoft Connect stopped at Mo, 25 Aug 2025 10:32:13
DEBUG    2025-08-25 10:32:13,868 [application.on_game_stopped:791]:Removing 57 from running IDs
DEBUG    2025-08-25 10:32:13,883 [path_cache.add_to_path_cache:47]:Adding Ubisoft Connect (wine) to path cache
INFO     2025-08-25 10:39:31,236 [application.do_shutdown:1047]:Shutting down Lutris

~ 7m 42s

I have already uninstalled Lutris, restarted my PC, and reinstalled it. The same error keeps occurring.

What can I do about this?

If it helps, here is my PC

inxi -Fzxi
System:
  Kernel: 6.16.2-2-cachyos arch: x86_64 bits: 64 compiler: gcc v: 15.2.1
  Desktop: KDE Plasma v: 6.4.4 Distro: CachyOS base: Arch Linux
Machine:
  Type: Desktop Mobo: ASRock model: X870 Riptide WiFi
    serial: <superuser required> UEFI: American Megatrends LLC. v: 3.30
    date: 06/16/2025
CPU:
  Info: 8-core model: AMD Ryzen 7 9800X3D bits: 64 type: MCP arch: N/A rev: 0
    cache: L1: 640 KiB L2: 8 MiB L3: 96 MiB
  Speed (MHz): avg: 5208 min/max: 603/5272 boost: enabled cores: 1: 5208
    2: 5208 3: 5208 4: 5208 5: 5208 6: 5208 7: 5208 8: 5208 bogomips: 75057
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm
Graphics:
  Device-1: NVIDIA GB202 [GeForce RTX 5090] vendor: Micro-Star MSI
    driver: nvidia v: 580.76.05 arch: Lovelace bus-ID: 01:00.0
  Device-2: Advanced Micro Devices [AMD/ATI] Granite Ridge [Radeon Graphics]
    vendor: ASRock driver: amdgpu v: kernel arch: RDNA-2 bus-ID: 71:00.0
    temp: 50.0 C
  Device-3: Razer USA Kiyo Pro driver: snd-usb-audio,uvcvideo type: USB
    bus-ID: 2-4.1.2:6
  Display: wayland server: X.org v: 1.21.1.18 with: Xwayland v: 24.1.8
    compositor: kwin_wayland driver: gpu: nv_platform,nvidia,nvidia-nvswitch
    resolution: 3840x2160~240Hz
  API: EGL v: 1.5 drivers: nvidia,radeonsi,swrast platforms:
    active: gbm,wayland,x11,surfaceless,device inactive: device-2
  API: OpenGL v: 4.6.0 compat-v: 4.5 vendor: nvidia mesa v: 580.76.05
    glx-v: 1.4 direct-render: yes renderer: NVIDIA GeForce RTX 5090/PCIe/SSE2
  API: Vulkan v: 1.4.321 drivers: nvidia,radv,llvmpipe surfaces: N/A
    devices: 3
  Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo
    de: kscreen-console,kscreen-doctor gpu: amdgpu_top, lact, nvidia-settings,
    nvidia-smi wl: wayland-info x11: xdpyinfo, xprop, xrandr
Audio:
  Device-1: NVIDIA driver: snd_hda_intel v: kernel bus-ID: 01:00.1
  Device-2: Advanced Micro Devices [AMD/ATI] Radeon High Definition Audio
    [Rembrandt/Strix] driver: snd_hda_intel v: kernel bus-ID: 71:00.1
  Device-3: Advanced Micro Devices [AMD] Family 17h/19h/1ah HD Audio
    driver: N/A bus-ID: 71:00.6
  Device-4: Generic USB Audio driver: hid-generic,snd-usb-audio,usbhid
    type: USB bus-ID: 1-10:15
  Device-5: Razer USA BlackShark V2 Pro
    driver: hid-generic,snd-usb-audio,usbhid type: USB bus-ID: 1-4.1.3:9
  Device-6: Razer USA Kiyo Pro driver: snd-usb-audio,uvcvideo type: USB
    bus-ID: 2-4.1.2:6
  Device-7: Razer USA Nommo Pro driver: razeraccessory,snd-usb-audio,usbhid
    type: USB bus-ID: 7-2:3
  API: ALSA v: k6.16.2-2-cachyos status: kernel-api
  Server-1: sndiod v: N/A status: off
  Server-2: JACK v: 1.9.22 status: off
  Server-3: PipeWire v: 1.4.7 status: active
Network:
  Device-1: MEDIATEK MT7925 Wi-Fi 7 160MHz driver: mt7925e v: kernel
    bus-ID: 08:00.0
  IF: wlan0 state: down mac: <filter>
  Device-2: Realtek Killer E3000 2.5GbE vendor: ASRock driver: r8169
    v: kernel port: b000 bus-ID: 09:00.0
  IF: enp9s0 state: up speed: 2500 Mbps duplex: full mac: <filter>
  IP v4: <filter> type: dynamic noprefixroute scope: global
  IP v6: <filter> type: dynamic noprefixroute scope: global
  IP v6: <filter> type: dynamic noprefixroute scope: global
  IP v6: <filter> type: noprefixroute scope: link
  WAN IP: <filter>
Bluetooth:
  Device-1: MediaTek Wireless_Device driver: btusb v: 0.8 type: USB
    bus-ID: 1-12:17
  Report: btmgmt ID: hci1 rfk-id: 1 state: up address: N/A
  Device-2: ASUSTek ASUS USB-BT500 driver: btusb v: 0.8 type: USB
    bus-ID: 1-7:10
  Report: ID: hci0 rfk-id: 0 state: up address: N/A
Drives:
  Local Storage: total: 6.37 TiB used: 4.46 TiB (70.1%)
  ID-1: /dev/nvme0n1 vendor: Samsung model: SSD 980 PRO 2TB size: 1.82 TiB
    temp: 41.9 C
  ID-2: /dev/nvme1n1 vendor: Samsung model: SSD 980 PRO 1TB size: 931.51 GiB
    temp: 42.9 C
  ID-3: /dev/nvme2n1 vendor: Samsung model: SSD 990 PRO 4TB size: 3.64 TiB
    temp: 39.9 C
Partition:
  ID-1: / size: 1.82 TiB used: 1.72 TiB (94.5%) fs: btrfs dev: /dev/nvme0n1p2
  ID-2: /boot size: 2.44 GiB used: 642.6 MiB (25.8%) fs: vfat
    dev: /dev/nvme0n1p1
  ID-3: /home size: 1.82 TiB used: 1.72 TiB (94.5%) fs: btrfs
    dev: /dev/nvme0n1p2
  ID-4: /var/log size: 1.82 TiB used: 1.72 TiB (94.5%) fs: btrfs
    dev: /dev/nvme0n1p2
  ID-5: /var/tmp size: 1.82 TiB used: 1.72 TiB (94.5%) fs: btrfs
    dev: /dev/nvme0n1p2
Swap:
  ID-1: swap-1 type: zram size: 60.41 GiB used: 1.5 MiB (0.0%) dev: /dev/zram0
Sensors:
  System Temperatures: cpu: 57.2 C mobo: 46.5 C gpu: amdgpu temp: 50.0 C
  Fan Speeds (rpm): N/A
Info:
  Memory: total: 60 GiB note: est. available: 60.41 GiB used: 6.39 GiB (10.6%)
  Processes: 381 Uptime: 18m Init: systemd
  Packages: 1650 Compilers: clang: 20.1.8 gcc: 15.2.1 Shell: fish v: 4.0.2
    inxi: 3.3.38

Best regards

//edit: Here is the Ubuntu pastebin link for the JSON file: Ubuntu Pastebin

What if you just launch Ubisoft Connect from Lutris interface and not an Ubisoft game?
What if you change Wine version to “GE-proton Latest”?

When I click on the “play” button on the left side of Lutris at Ubisoft, it takes a moment and then I get the same error message as the one in my screenshot from post 1.

Where exactly, or what exactly, should I start with “GE-proton Latest”? The game, or the Ubisoft launcher? And how, or where, do I set that?

Sorry, I’m not that familiar with Linux and Lutris yet.

Edit: When I start Assassin’s Creed Shadows with “GE-proton Latest,” nothing happens. I don’t get an error message either. See image.

This would be the terminal output:

lutris -d
INFO     2025-08-26 09:27:54,572 [application.do_command_line:478]:Starting Lutris 0.5.19
INFO     2025-08-26 09:27:54,678 [startup.run_all_checks:120]:"card1" is NVIDIA GeForce RTX 5090 (10de:2b85 1462:5306 nvidia) Driver 580.76.05
INFO     2025-08-26 09:27:54,696 [startup.run_all_checks:120]:"card0" is AMD Radeon Graphics (1002:13c0 1849:364e amdgpu) Driver None
DEBUG    2025-08-26 09:27:54,745 [xrandr.get_resolutions:91]:Retrieving resolution list
DEBUG    2025-08-26 09:27:54,746 [xrandr._get_vidmodes:18]:Retrieving 40 video modes from XrandR
DEBUG    2025-08-26 09:27:54,764 [path_cache._update_missing_games:114]:Checking for missing games
DEBUG    2025-08-26 09:27:54,774 [api.check_stale_runtime_versions:52]:Modified at Di 26 Aug 2025 09:22:15 , will update after Di 26 Aug 2025 15:22:15 
DEBUG    2025-08-26 09:27:54,775 [lutriswindow.create_runtime_updater_cb:1384]:Runtime up to date
DEBUG    2025-08-26 09:27:55,765 [http._request:88]:POST https://lutris.net/api/users/library?since=1756192936
DEBUG    2025-08-26 09:27:55,903 [game.save:459]:Saving Ubisoft Connect (wine) with config ID ubisoft-connect-latest-1756110362
DEBUG    2025-08-26 09:27:55,903 [config.save:235]:Saving LutrisConfig(level=game, game_config_id=ubisoft-connect-latest-1756110362, runner=wine) config to /home/sascha/.local/share/lutris/games/ubisoft-connect-latest-1756110362.yml
DEBUG    2025-08-26 09:27:55,945 [path_cache.add_to_path_cache:47]:Adding Ubisoft Connect (wine) to path cache
DEBUG    2025-08-26 09:28:00,417 [xrandr.get_resolutions:91]:Retrieving resolution list
DEBUG    2025-08-26 09:28:00,418 [xrandr._get_vidmodes:18]:Retrieving 40 video modes from XrandR
DEBUG    2025-08-26 09:28:04,609 [xrandr.get_outputs:26]:Retrieving display outputs
DEBUG    2025-08-26 09:28:04,610 [xrandr._get_vidmodes:18]:Retrieving 40 video modes from XrandR
Started initial process 4876 from gamemoderun mangohud /usr/bin/umu-run /home/sascha/Games/ubisoft-connect/drive_c/Program Files (x86)/Ubisoft/Ubisoft Game Launcher/UbisoftConnect.exe uplay://launch/1a99b369-2931-4b22-96a4-9a0b58e586e8
Start monitoring process.
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
[umu.__main__:78] DEBUG: SHELL=/bin/fish
[umu.__main__:78] DEBUG: SESSION_MANAGER=local/cachyos-sascha:@/tmp/.ICE-unix/1246,unix/cachyos-sascha:/tmp/.ICE-unix/1246
[umu.__main__:78] DEBUG: WINDOWID=94311093279312
[umu.__main__:78] DEBUG: COLORTERM=truecolor
[umu.__main__:78] DEBUG: XDG_CONFIG_DIRS=/home/sascha/.config/kdedefaults:/etc/xdg
[umu.__main__:78] DEBUG: XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session0
[umu.__main__:78] DEBUG: XDG_MENU_PREFIX=plasma-
[umu.__main__:78] DEBUG: ICEAUTHORITY=/run/user/1000/iceauth_VnxHGn
[umu.__main__:78] DEBUG: LANGUAGE=
[umu.__main__:78] DEBUG: LC_ADDRESS=de_DE.UTF-8
[umu.__main__:78] DEBUG: LC_NAME=de_DE.UTF-8
[umu.__main__:78] DEBUG: __GL_SHADER_DISK_CACHE_PATH=/home/sascha/Games/ubisoft-connect
[umu.__main__:78] DEBUG: SHELL_SESSION_ID=90c869235199404c9e2ab3070297a04d
[umu.__main__:78] DEBUG: DRI_PRIME=1002:13c0
[umu.__main__:78] DEBUG: MEMORY_PRESSURE_WRITE=c29tZSAyMDAwMDAgMjAwMDAwMAA=
[umu.__main__:78] DEBUG: LIBVA_DRIVER_NAME=nvidia
[umu.__main__:78] DEBUG: DESKTOP_SESSION=plasma
[umu.__main__:78] DEBUG: LC_MONETARY=de_DE.UTF-8
[umu.__main__:78] DEBUG: GTK_RC_FILES=/etc/gtk/gtkrc:/home/sascha/.gtkrc:/home/sascha/.config/gtkrc
[umu.__main__:78] DEBUG: WINE_MONO_CACHE_DIR=/home/sascha/.local/share/lutris/runners/proton/Proton-GE Latest/files/mono
[umu.__main__:78] DEBUG: XDG_SEAT=seat0
[umu.__main__:78] DEBUG: PWD=/home/sascha/Games/ubisoft-connect/drive_c/Program Files (x86)/Ubisoft/Ubisoft Game Launcher
[umu.__main__:78] DEBUG: XDG_SESSION_DESKTOP=KDE
[umu.__main__:78] DEBUG: LOGNAME=sascha
[umu.__main__:78] DEBUG: GAME_DIRECTORY=/home/sascha/Games/ubisoft-connect
[umu.__main__:78] DEBUG: XDG_SESSION_TYPE=wayland
[umu.__main__:78] DEBUG: SYSTEMD_EXEC_PID=1267
[umu.__main__:78] DEBUG: XAUTHORITY=/run/user/1000/xauth_sWAsfs
[umu.__main__:78] DEBUG: WINEESYNC=1
[umu.__main__:78] DEBUG: LUTRIS_GAME_UUID=caf010d9-bc6f-4a21-9462-02eacadc0cb4
[umu.__main__:78] DEBUG: MOTD_SHOWN=pam
[umu.__main__:78] DEBUG: LD_PRELOAD=libgamemodeauto.so.0:/usr/$LIB/mangohud/libMangoHud_shim.so
[umu.__main__:78] DEBUG: GTK2_RC_FILES=/etc/gtk-2.0/gtkrc:/home/sascha/.gtkrc-2.0:/home/sascha/.config/gtkrc-2.0
[umu.__main__:78] DEBUG: WINEARCH=win64
[umu.__main__:78] DEBUG: HOME=/home/sascha
[umu.__main__:78] DEBUG: MANGOHUD=1
[umu.__main__:78] DEBUG: LANG=de_DE.UTF-8
[umu.__main__:78] DEBUG: LC_PAPER=de_DE.UTF-8
[umu.__main__:78] DEBUG: STORE=ubisoft
[umu.__main__:78] DEBUG: RUSTICL_ENABLE=radeonsi
[umu.__main__:78] DEBUG: WINEPREFIX=/home/sascha/Games/ubisoft-connect
[umu.__main__:78] DEBUG: XDG_CURRENT_DESKTOP=KDE
[umu.__main__:78] DEBUG: KONSOLE_DBUS_SERVICE=:1.206
[umu.__main__:78] DEBUG: MEMORY_PRESSURE_WATCH=/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/session.slice/plasma-plasmashell.service/memory.pressure
[umu.__main__:78] DEBUG: DXVK_LOG_LEVEL=error
[umu.__main__:78] DEBUG: WAYLAND_DISPLAY=wayland-0
[umu.__main__:78] DEBUG: WEBKIT_DISABLE_DMABUF_RENDERER=1
[umu.__main__:78] DEBUG: KONSOLE_DBUS_SESSION=/Sessions/1
[umu.__main__:78] DEBUG: PROFILEHOME=
[umu.__main__:78] DEBUG: VIRTUAL_ENV_DISABLE_PROMPT=1
[umu.__main__:78] DEBUG: MANROFFOPT=-c
[umu.__main__:78] DEBUG: XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0
[umu.__main__:78] DEBUG: INVOCATION_ID=bc20ace5fb0449228907bd49644f93c1
[umu.__main__:78] DEBUG: KONSOLE_VERSION=250800
[umu.__main__:78] DEBUG: MANAGERPID=1043
[umu.__main__:78] DEBUG: DXVK_ENABLE_NVAPI=1
[umu.__main__:78] DEBUG: PROTON_VERB=waitforexitandrun
[umu.__main__:78] DEBUG: KDE_SESSION_UID=1000
[umu.__main__:78] DEBUG: XKB_DEFAULT_LAYOUT=de
[umu.__main__:78] DEBUG: WINEDLLOVERRIDES=winemenubuilder=
[umu.__main__:78] DEBUG: XDG_SESSION_CLASS=user
[umu.__main__:78] DEBUG: VK_DRIVER_FILES=/usr/share/vulkan/icd.d/radeon_icd.i686.json:/usr/share/vulkan/icd.d/radeon_icd.x86_64.json
[umu.__main__:78] DEBUG: LC_IDENTIFICATION=de_DE.UTF-8
[umu.__main__:78] DEBUG: TERM=xterm-256color
[umu.__main__:78] DEBUG: __GL_SHADER_DISK_CACHE=1
[umu.__main__:78] DEBUG: PROTON_EAC_RUNTIME=/home/sascha/.local/share/lutris/runtime/eac_runtime
[umu.__main__:78] DEBUG: USER=sascha
[umu.__main__:78] DEBUG: WINE_LARGE_ADDRESS_AWARE=1
[umu.__main__:78] DEBUG: COLORFGBG=15;0
[umu.__main__:78] DEBUG: QT_WAYLAND_RECONNECT=1
[umu.__main__:78] DEBUG: KDE_SESSION_VERSION=6
[umu.__main__:78] DEBUG: GAME_NAME=Assassin's Creed Shadows
[umu.__main__:78] DEBUG: MANPAGER=sh -c 'col -bx | bat -l man -p'
[umu.__main__:78] DEBUG: DISPLAY=:0
[umu.__main__:78] DEBUG: GSK_RENDERER=ngl
[umu.__main__:78] DEBUG: SHLVL=1
[umu.__main__:78] DEBUG: WINE_GECKO_CACHE_DIR=/home/sascha/.local/share/lutris/runners/proton/Proton-GE Latest/files/gecko
[umu.__main__:78] DEBUG: LC_TELEPHONE=de_DE.UTF-8
[umu.__main__:78] DEBUG: LC_MEASUREMENT=de_DE.UTF-8
[umu.__main__:78] DEBUG: XDG_VTNR=1
[umu.__main__:78] DEBUG: XDG_SESSION_ID=1
[umu.__main__:78] DEBUG: WINEDEBUG=-all
[umu.__main__:78] DEBUG: LD_LIBRARY_PATH=/home/sascha/.local/share/Steam/compatibilitytools.d/Proton-GE Latest/files/lib:/usr/lib:/usr/lib32:/usr/lib/libfakeroot:/usr/lib64:/home/sascha/.local/share/lutris/runtime/Ubuntu-18.04-i686:/home/sascha/.local/share/lutris/runtime/steam/i386/lib/i386-linux-gnu:/home/sascha/.local/share/lutris/runtime/steam/i386/lib:/home/sascha/.local/share/lutris/runtime/steam/i386/usr/lib/i386-linux-gnu:/home/sascha/.local/share/lutris/runtime/steam/i386/usr/lib:/home/sascha/.local/share/lutris/runtime/Ubuntu-18.04-x86_64:/home/sascha/.local/share/lutris/runtime/steam/amd64/lib/x86_64-linux-gnu:/home/sascha/.local/share/lutris/runtime/steam/amd64/lib:/home/sascha/.local/share/lutris/runtime/steam/amd64/usr/lib/x86_64-linux-gnu:/home/sascha/.local/share/lutris/runtime/steam/amd64/usr/lib
[umu.__main__:78] DEBUG: MANGOHUD_DLSYM=1
[umu.__main__:78] DEBUG: XDG_RUNTIME_DIR=/run/user/1000
[umu.__main__:78] DEBUG: VK_ICD_FILENAMES=/usr/share/vulkan/icd.d/radeon_icd.i686.json:/usr/share/vulkan/icd.d/radeon_icd.x86_64.json
[umu.__main__:78] DEBUG: DEBUGINFOD_URLS=https://debuginfod.cachyos.org https://debuginfod.archlinux.org 
[umu.__main__:78] DEBUG: LC_TIME=de_DE.UTF-8
[umu.__main__:78] DEBUG: JOURNAL_STREAM=9:17242
[umu.__main__:78] DEBUG: KDE_FULL_SESSION=true
[umu.__main__:78] DEBUG: PROTON_DXVK_D3D8=1
[umu.__main__:78] DEBUG: PATH=/home/sascha/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/lib/jvm/default/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl
[umu.__main__:78] DEBUG: PROTONPATH=/home/sascha/.local/share/Steam/compatibilitytools.d/Proton-GE Latest
[umu.__main__:78] DEBUG: DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
[umu.__main__:78] DEBUG: KDE_APPLICATIONS_AS_SCOPE=1
[umu.__main__:78] DEBUG: WINE=/home/sascha/.local/share/Steam/compatibilitytools.d/Proton-GE Latest/files/bin/wine
[umu.__main__:78] DEBUG: MAIL=/var/spool/mail/sascha
[umu.__main__:78] DEBUG: UMU_LOG=1
[umu.__main__:78] DEBUG: WINEFSYNC=1
[umu.__main__:78] DEBUG: LC_NUMERIC=de_DE.UTF-8
[umu.__main__:78] DEBUG: WINE_FULLSCREEN_FSR=1
[umu.__main__:78] DEBUG: DXVK_NVAPIHACK=0
[umu.__main__:78] DEBUG: PROTON_BATTLEYE_RUNTIME=/home/sascha/.local/share/lutris/runtime/battleye_runtime
[umu.__main__:78] DEBUG: GAMEID=umu-default
[umu.__main__:78] DEBUG: KONSOLE_DBUS_WINDOW=/Windows/1
[umu.umu_run:797] INFO: umu-launcher version 1.2.9 (3.13.5 (main, Jun 21 2025, 15:15:57) [GCC 15.1.1 20250425])
[umu.umu_run:803] DEBUG: Connecting to '1.1.1.1'...
[umu.umu_run:715] DEBUG: PROTONPATH set, resolving its required runtime
[umu.umu_runtime:270] DEBUG: Local: /home/sascha/.local/share/umu/steamrt3
[umu.umu_runtime:315] DEBUG: Existing install detected
[umu.umu_runtime:316] DEBUG: Using container runtime 'steamrt3' aka 'sniper'
[umu.umu_runtime:317] DEBUG: Checking updates for 'steamrt3'...
[umu.umu_runtime:361] DEBUG: Sending request to 'repo.steampowered.com/steamrt-images-sniper/snapshots/latest-container-runtime-public-beta/VERSION.txt?version=GUGnMNTGOopGE1BdoM8frg' for 'VERSION.txt'...
[umu.umu_runtime:468] DEBUG: Acquiring file lock '/home/sascha/.local/share/umu/umu.lock'...
[umu.umu_runtime:470] DEBUG: Acquired file lock '/home/sascha/.local/share/umu/umu.lock'
[umu.umu_runtime:475] DEBUG: Released file lock '/home/sascha/.local/share/umu/umu.lock'
[umu.umu_runtime:370] INFO: steamrt3 is up to date
[umu.umu_run:910] DEBUG: WINEPREFIX=/home/sascha/Games/ubisoft-connect
[umu.umu_run:910] DEBUG: GAMEID=umu-default
[umu.umu_run:910] DEBUG: PROTON_CRASH_REPORT_DIR=/tmp/umu_crashreports
[umu.umu_run:910] DEBUG: PROTONPATH=/home/sascha/.local/share/Steam/compatibilitytools.d/Proton-GE Latest
[umu.umu_run:910] DEBUG: STEAM_COMPAT_APP_ID=default
[umu.umu_run:910] DEBUG: STEAM_COMPAT_TOOL_PATHS=/home/sascha/.local/share/Steam/compatibilitytools.d/Proton-GE Latest:/home/sascha/.local/share/umu/steamrt3
[umu.umu_run:910] DEBUG: STEAM_COMPAT_LIBRARY_PATHS=/home
[umu.umu_run:910] DEBUG: STEAM_COMPAT_MOUNTS=/home/sascha/.local/share/Steam/compatibilitytools.d/Proton-GE Latest:/home/sascha/.local/share/umu/steamrt3
[umu.umu_run:910] DEBUG: STEAM_COMPAT_INSTALL_PATH=/home/sascha/Games/ubisoft-connect/drive_c/Program Files (x86)/Ubisoft/Ubisoft Game Launcher
[umu.umu_run:910] DEBUG: STEAM_COMPAT_CLIENT_INSTALL_PATH=
[umu.umu_run:910] DEBUG: STEAM_COMPAT_DATA_PATH=/home/sascha/Games/ubisoft-connect
[umu.umu_run:910] DEBUG: STEAM_COMPAT_SHADER_PATH=/home/sascha/Games/ubisoft-connect/shadercache
[umu.umu_run:910] DEBUG: FONTCONFIG_PATH=
[umu.umu_run:910] DEBUG: EXE=/home/sascha/Games/ubisoft-connect/drive_c/Program Files (x86)/Ubisoft/Ubisoft Game Launcher/UbisoftConnect.exe
[umu.umu_run:910] DEBUG: SteamAppId=default
[umu.umu_run:910] DEBUG: SteamGameId=default
[umu.umu_run:910] DEBUG: STEAM_RUNTIME_LIBRARY_PATH=/home/sascha/.local/share/lutris/runtime/Ubuntu-18.04-x86_64:/home/sascha/.local/share/lutris/runtime/steam/amd64/usr/lib:/home/sascha/.local/share/lutris/runtime/steam/amd64/lib/x86_64-linux-gnu:/home/sascha/Games/ubisoft-connect/drive_c/Program Files (x86)/Ubisoft/Ubisoft Game Launcher:/usr/lib/libfakeroot:/home/sascha/.local/share/lutris/runtime/steam/i386/lib:/usr/lib64:/home/sascha/.local/share/lutris/runtime/steam/i386/usr/lib/i386-linux-gnu:/home/sascha/.local/share/lutris/runtime/steam/amd64/lib:/usr/lib32:/home/sascha/.local/share/lutris/runtime/steam/i386/usr/lib:/home/sascha/.local/share/lutris/runtime/steam/amd64/usr/lib/x86_64-linux-gnu:/home/sascha/.local/share/lutris/runtime/steam/i386/lib/i386-linux-gnu:/home/sascha/.local/share/lutris/runtime/Ubuntu-18.04-i686:/home/sascha/.local/share/Steam/compatibilitytools.d/Proton-GE Latest/files/lib:/usr/lib
[umu.umu_run:910] DEBUG: STORE=ubisoft
[umu.umu_run:910] DEBUG: PROTON_VERB=waitforexitandrun
[umu.umu_run:910] DEBUG: UMU_ID=umu-default
[umu.umu_run:910] DEBUG: UMU_ZENITY=
[umu.umu_run:910] DEBUG: UMU_NO_RUNTIME=
[umu.umu_run:910] DEBUG: UMU_RUNTIME_UPDATE=
[umu.umu_run:910] DEBUG: UMU_NO_PROTON=
[umu.umu_run:910] DEBUG: RUNTIMEPATH=/home/sascha/.local/share/umu/steamrt3
[umu.umu_run:910] DEBUG: UMU_STEAM_GAME_ID=
[umu.umu_run:910] DEBUG: UMU_INVOCATION_ID=aa8cf79130752350c9687279ba92123f
[umu.umu_run:921] DEBUG: (PosixPath('/home/sascha/.local/share/umu/steamrt3/umu'), '--verb', 'waitforexitandrun', '--', PosixPath('/home/sascha/.local/share/umu/umu-shim'), PosixPath('/home/sascha/.local/share/Steam/compatibilitytools.d/Proton-GE Latest/proton'), 'waitforexitandrun', '/home/sascha/Games/ubisoft-connect/drive_c/Program Files (x86)/Ubisoft/Ubisoft Game Launcher/UbisoftConnect.exe', 'uplay://launch/1a99b369-2931-4b22-96a4-9a0b58e586e8')
[umu.umu_run:664] DEBUG: prctl PR_SET_CHILD_SUBREAPER exited with status: 0
ProtonFixes[5005] WARN: [CONFIG]: Parent directory "/home/sascha/.config/protonfixes" does not exist. Abort.
Traceback (most recent call last):
  File "/home/sascha/.local/share/Steam/compatibilitytools.d/Proton-GE Latest/proton", line 2180, in <module>
    protonfixes.setup_mount_drives(setup_dir_drive)
  File "/home/sascha/.local/share/Steam/compatibilitytools.d/Proton-GE Latest/protonfixes/__init__.py", line 102, in setup_mount_drives
    if os.path.exists(directory) and not _is_directory_empty(directory):
  File "/home/sascha/.local/share/Steam/compatibilitytools.d/Proton-GE Latest/protonfixes/__init__.py", line 88, in _is_directory_empty
    return not any(os.scandir(dir_path))
PermissionError: [Errno 13] Permission denied: '/mnt'
[umu.umu_run:681] DEBUG: Child 4893 exited with wait status: 256
[umu.umu_run:683] INFO: [Errno 10] No child processes
Monitored process exited.
Initial process has exited (return code: 0)
All processes have quit
Exit with return code 0
DEBUG    2025-08-26 09:28:05,360 [monitored_command.on_stop:232]:Process 4874 has terminated with code 0
DEBUG    2025-08-26 09:28:06,613 [game.beat:910]:Game thread stopped
WARNING  2025-08-26 09:28:06,613 [game.on_game_quit:948]:Game still running (state: running)
INFO     2025-08-26 09:28:06,613 [game.stop:921]:Stopping Assassin's Creed Shadows (wine)
DEBUG    2025-08-26 09:28:06,614 [game.stop_game:877]:Assassin's Creed Shadows (wine) has run for 2 seconds
WARNING  2025-08-26 09:28:06,614 [game.stop_game:879]:The game has run for a very short time, did it crash?
DEBUG    2025-08-26 09:28:06,614 [game.stop_game:889]:Playtime: 1 minute
DEBUG    2025-08-26 09:28:06,614 [game.on_game_quit:966]:Assassin's Creed Shadows stopped at Di, 26 Aug 2025 09:28:06
DEBUG    2025-08-26 09:28:06,639 [application.on_game_stopped:791]:Removing 48 from running IDs
DEBUG    2025-08-26 09:28:06,658 [path_cache.add_to_path_cache:47]:Adding Assassin's Creed Shadows (wine) to path cache

edit2:
I have now also set “GE-proton Latest” in Ubisoft. See the image below.

And here is the terminal output:

lutris -d
INFO     2025-08-26 09:43:32,907 [application.do_command_line:478]:Starting Lutris 0.5.19
INFO     2025-08-26 09:43:33,013 [startup.run_all_checks:120]:"card1" is NVIDIA GeForce RTX 5090 (10de:2b85 1462:5306 nvidia) Driver 580.76.05
INFO     2025-08-26 09:43:33,032 [startup.run_all_checks:120]:"card0" is AMD Radeon Graphics (1002:13c0 1849:364e amdgpu) Driver None
DEBUG    2025-08-26 09:43:33,083 [xrandr.get_resolutions:91]:Retrieving resolution list
DEBUG    2025-08-26 09:43:33,083 [xrandr._get_vidmodes:18]:Retrieving 40 video modes from XrandR
DEBUG    2025-08-26 09:43:33,103 [path_cache._update_missing_games:114]:Checking for missing games
DEBUG    2025-08-26 09:43:33,114 [api.check_stale_runtime_versions:52]:Modified at Di 26 Aug 2025 09:22:15 , will update after Di 26 Aug 2025 15:22:15 
DEBUG    2025-08-26 09:43:33,114 [lutriswindow.create_runtime_updater_cb:1384]:Runtime up to date
DEBUG    2025-08-26 09:43:34,105 [http._request:88]:POST https://lutris.net/api/users/library?since=1756194109
DEBUG    2025-08-26 09:43:40,923 [xrandr.get_resolutions:91]:Retrieving resolution list
DEBUG    2025-08-26 09:43:40,924 [xrandr._get_vidmodes:18]:Retrieving 40 video modes from XrandR
DEBUG    2025-08-26 09:44:10,578 [game.save:459]:Saving Ubisoft Connect (wine) with config ID ubisoft-connect-latest-1756110362
DEBUG    2025-08-26 09:44:10,578 [config.save:235]:Saving LutrisConfig(level=game, game_config_id=ubisoft-connect-latest-1756110362, runner=wine) config to /home/sascha/.local/share/lutris/games/ubisoft-connect-latest-1756110362.yml
DEBUG    2025-08-26 09:44:10,622 [path_cache.add_to_path_cache:47]:Adding Ubisoft Connect (wine) to path cache
DEBUG    2025-08-26 09:44:13,215 [xrandr.get_outputs:26]:Retrieving display outputs
DEBUG    2025-08-26 09:44:13,216 [xrandr._get_vidmodes:18]:Retrieving 40 video modes from XrandR
Started initial process 14512 from gamemoderun mangohud /usr/bin/umu-run /home/sascha/Games/ubisoft-connect/drive_c/Program Files (x86)/Ubisoft/Ubisoft Game Launcher/UbisoftConnect.exe
Start monitoring process.
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
[umu.__main__:78] DEBUG: SHELL=/bin/fish
[umu.__main__:78] DEBUG: SESSION_MANAGER=local/cachyos-sascha:@/tmp/.ICE-unix/1246,unix/cachyos-sascha:/tmp/.ICE-unix/1246
[umu.__main__:78] DEBUG: WINDOWID=94016161367664
[umu.__main__:78] DEBUG: COLORTERM=truecolor
[umu.__main__:78] DEBUG: XDG_CONFIG_DIRS=/home/sascha/.config/kdedefaults:/etc/xdg
[umu.__main__:78] DEBUG: XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session0
[umu.__main__:78] DEBUG: XDG_MENU_PREFIX=plasma-
[umu.__main__:78] DEBUG: ICEAUTHORITY=/run/user/1000/iceauth_VnxHGn
[umu.__main__:78] DEBUG: LANGUAGE=
[umu.__main__:78] DEBUG: LC_ADDRESS=de_DE.UTF-8
[umu.__main__:78] DEBUG: LC_NAME=de_DE.UTF-8
[umu.__main__:78] DEBUG: __GL_SHADER_DISK_CACHE_PATH=/home/sascha/Games/ubisoft-connect
[umu.__main__:78] DEBUG: SHELL_SESSION_ID=00b6be86253a4cc6ab30982d1489e9b4
[umu.__main__:78] DEBUG: DRI_PRIME=1002:13c0
[umu.__main__:78] DEBUG: MEMORY_PRESSURE_WRITE=c29tZSAyMDAwMDAgMjAwMDAwMAA=
[umu.__main__:78] DEBUG: LIBVA_DRIVER_NAME=nvidia
[umu.__main__:78] DEBUG: DESKTOP_SESSION=plasma
[umu.__main__:78] DEBUG: LC_MONETARY=de_DE.UTF-8
[umu.__main__:78] DEBUG: GTK_RC_FILES=/etc/gtk/gtkrc:/home/sascha/.gtkrc:/home/sascha/.config/gtkrc
[umu.__main__:78] DEBUG: WINE_MONO_CACHE_DIR=/home/sascha/.local/share/lutris/runners/proton/ge-proton/files/mono
[umu.__main__:78] DEBUG: XDG_SEAT=seat0
[umu.__main__:78] DEBUG: PWD=/home/sascha/Games/ubisoft-connect/drive_c/Program Files (x86)/Ubisoft/Ubisoft Game Launcher
[umu.__main__:78] DEBUG: XDG_SESSION_DESKTOP=KDE
[umu.__main__:78] DEBUG: LOGNAME=sascha
[umu.__main__:78] DEBUG: GAME_DIRECTORY=/home/sascha/Games/ubisoft-connect
[umu.__main__:78] DEBUG: XDG_SESSION_TYPE=wayland
[umu.__main__:78] DEBUG: SYSTEMD_EXEC_PID=1267
[umu.__main__:78] DEBUG: XAUTHORITY=/run/user/1000/xauth_sWAsfs
[umu.__main__:78] DEBUG: WINEESYNC=1
[umu.__main__:78] DEBUG: LUTRIS_GAME_UUID=965e3657-abd9-45c7-8b11-a4a2252cea07
[umu.__main__:78] DEBUG: MOTD_SHOWN=pam
[umu.__main__:78] DEBUG: LD_PRELOAD=libgamemodeauto.so.0:/usr/$LIB/mangohud/libMangoHud_shim.so
[umu.__main__:78] DEBUG: GTK2_RC_FILES=/etc/gtk-2.0/gtkrc:/home/sascha/.gtkrc-2.0:/home/sascha/.config/gtkrc-2.0
[umu.__main__:78] DEBUG: WINEARCH=win64
[umu.__main__:78] DEBUG: HOME=/home/sascha
[umu.__main__:78] DEBUG: MANGOHUD=1
[umu.__main__:78] DEBUG: LC_PAPER=de_DE.UTF-8
[umu.__main__:78] DEBUG: LANG=de_DE.UTF-8
[umu.__main__:78] DEBUG: STORE=none
[umu.__main__:78] DEBUG: RUSTICL_ENABLE=radeonsi
[umu.__main__:78] DEBUG: WINEPREFIX=/home/sascha/Games/ubisoft-connect
[umu.__main__:78] DEBUG: XDG_CURRENT_DESKTOP=KDE
[umu.__main__:78] DEBUG: KONSOLE_DBUS_SERVICE=:1.298
[umu.__main__:78] DEBUG: MEMORY_PRESSURE_WATCH=/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/session.slice/plasma-plasmashell.service/memory.pressure
[umu.__main__:78] DEBUG: DXVK_LOG_LEVEL=error
[umu.__main__:78] DEBUG: WAYLAND_DISPLAY=wayland-0
[umu.__main__:78] DEBUG: WEBKIT_DISABLE_DMABUF_RENDERER=1
[umu.__main__:78] DEBUG: KONSOLE_DBUS_SESSION=/Sessions/1
[umu.__main__:78] DEBUG: PROFILEHOME=
[umu.__main__:78] DEBUG: VIRTUAL_ENV_DISABLE_PROMPT=1
[umu.__main__:78] DEBUG: MANROFFOPT=-c
[umu.__main__:78] DEBUG: XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0
[umu.__main__:78] DEBUG: INVOCATION_ID=bc20ace5fb0449228907bd49644f93c1
[umu.__main__:78] DEBUG: KONSOLE_VERSION=250800
[umu.__main__:78] DEBUG: MANAGERPID=1043
[umu.__main__:78] DEBUG: DXVK_ENABLE_NVAPI=1
[umu.__main__:78] DEBUG: PROTON_VERB=waitforexitandrun
[umu.__main__:78] DEBUG: KDE_SESSION_UID=1000
[umu.__main__:78] DEBUG: XKB_DEFAULT_LAYOUT=de
[umu.__main__:78] DEBUG: WINEDLLOVERRIDES=winemenubuilder=
[umu.__main__:78] DEBUG: XDG_SESSION_CLASS=user
[umu.__main__:78] DEBUG: VK_DRIVER_FILES=/usr/share/vulkan/icd.d/radeon_icd.i686.json:/usr/share/vulkan/icd.d/radeon_icd.x86_64.json
[umu.__main__:78] DEBUG: TERM=xterm-256color
[umu.__main__:78] DEBUG: LC_IDENTIFICATION=de_DE.UTF-8
[umu.__main__:78] DEBUG: __GL_SHADER_DISK_CACHE=1
[umu.__main__:78] DEBUG: PROTON_EAC_RUNTIME=/home/sascha/.local/share/lutris/runtime/eac_runtime
[umu.__main__:78] DEBUG: USER=sascha
[umu.__main__:78] DEBUG: WINE_LARGE_ADDRESS_AWARE=1
[umu.__main__:78] DEBUG: COLORFGBG=15;0
[umu.__main__:78] DEBUG: QT_WAYLAND_RECONNECT=1
[umu.__main__:78] DEBUG: KDE_SESSION_VERSION=6
[umu.__main__:78] DEBUG: GAME_NAME=Ubisoft Connect
[umu.__main__:78] DEBUG: MANPAGER=sh -c 'col -bx | bat -l man -p'
[umu.__main__:78] DEBUG: DISPLAY=:0
[umu.__main__:78] DEBUG: GSK_RENDERER=ngl
[umu.__main__:78] DEBUG: SHLVL=1
[umu.__main__:78] DEBUG: WINE_GECKO_CACHE_DIR=/home/sascha/.local/share/lutris/runners/proton/ge-proton/files/gecko
[umu.__main__:78] DEBUG: LC_TELEPHONE=de_DE.UTF-8
[umu.__main__:78] DEBUG: LC_MEASUREMENT=de_DE.UTF-8
[umu.__main__:78] DEBUG: XDG_VTNR=1
[umu.__main__:78] DEBUG: XDG_SESSION_ID=1
[umu.__main__:78] DEBUG: WINEDEBUG=-all
[umu.__main__:78] DEBUG: LD_LIBRARY_PATH=/home/sascha/.local/share/lutris/runners/proton/ge-proton/files/lib:/usr/lib:/usr/lib32:/usr/lib/libfakeroot:/usr/lib64:/home/sascha/.local/share/lutris/runtime/Ubuntu-18.04-i686:/home/sascha/.local/share/lutris/runtime/steam/i386/lib/i386-linux-gnu:/home/sascha/.local/share/lutris/runtime/steam/i386/lib:/home/sascha/.local/share/lutris/runtime/steam/i386/usr/lib/i386-linux-gnu:/home/sascha/.local/share/lutris/runtime/steam/i386/usr/lib:/home/sascha/.local/share/lutris/runtime/Ubuntu-18.04-x86_64:/home/sascha/.local/share/lutris/runtime/steam/amd64/lib/x86_64-linux-gnu:/home/sascha/.local/share/lutris/runtime/steam/amd64/lib:/home/sascha/.local/share/lutris/runtime/steam/amd64/usr/lib/x86_64-linux-gnu:/home/sascha/.local/share/lutris/runtime/steam/amd64/usr/lib
[umu.__main__:78] DEBUG: MANGOHUD_DLSYM=1
[umu.__main__:78] DEBUG: XDG_RUNTIME_DIR=/run/user/1000
[umu.__main__:78] DEBUG: VK_ICD_FILENAMES=/usr/share/vulkan/icd.d/radeon_icd.i686.json:/usr/share/vulkan/icd.d/radeon_icd.x86_64.json
[umu.__main__:78] DEBUG: DEBUGINFOD_URLS=https://debuginfod.cachyos.org https://debuginfod.archlinux.org 
[umu.__main__:78] DEBUG: LC_TIME=de_DE.UTF-8
[umu.__main__:78] DEBUG: JOURNAL_STREAM=9:17242
[umu.__main__:78] DEBUG: KDE_FULL_SESSION=true
[umu.__main__:78] DEBUG: PROTON_DXVK_D3D8=1
[umu.__main__:78] DEBUG: PATH=/home/sascha/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/lib/jvm/default/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl
[umu.__main__:78] DEBUG: PROTONPATH=/home/sascha/.local/share/lutris/runners/proton/ge-proton
[umu.__main__:78] DEBUG: DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
[umu.__main__:78] DEBUG: KDE_APPLICATIONS_AS_SCOPE=1
[umu.__main__:78] DEBUG: WINE=/home/sascha/.local/share/lutris/runners/proton/ge-proton/files/bin/wine
[umu.__main__:78] DEBUG: MAIL=/var/spool/mail/sascha
[umu.__main__:78] DEBUG: UMU_LOG=1
[umu.__main__:78] DEBUG: WINEFSYNC=1
[umu.__main__:78] DEBUG: LC_NUMERIC=de_DE.UTF-8
[umu.__main__:78] DEBUG: WINE_FULLSCREEN_FSR=1
[umu.__main__:78] DEBUG: DXVK_NVAPIHACK=0
[umu.__main__:78] DEBUG: PROTON_BATTLEYE_RUNTIME=/home/sascha/.local/share/lutris/runtime/battleye_runtime
[umu.__main__:78] DEBUG: GAMEID=umu-default
[umu.__main__:78] DEBUG: KONSOLE_DBUS_WINDOW=/Windows/1
[umu.umu_run:797] INFO: umu-launcher version 1.2.9 (3.13.5 (main, Jun 21 2025, 15:15:57) [GCC 15.1.1 20250425])
[umu.umu_run:803] DEBUG: Connecting to '1.1.1.1'...
[umu.umu_run:715] DEBUG: PROTONPATH set, resolving its required runtime
[umu.umu_runtime:270] DEBUG: Local: /home/sascha/.local/share/umu/steamrt3
[umu.umu_runtime:315] DEBUG: Existing install detected
[umu.umu_runtime:316] DEBUG: Using container runtime 'steamrt3' aka 'sniper'
[umu.umu_runtime:317] DEBUG: Checking updates for 'steamrt3'...
[umu.umu_runtime:361] DEBUG: Sending request to 'repo.steampowered.com/steamrt-images-sniper/snapshots/latest-container-runtime-public-beta/VERSION.txt?version=r_3-OCWwHrvj5riC2CSTgA' for 'VERSION.txt'...
[umu.umu_runtime:468] DEBUG: Acquiring file lock '/home/sascha/.local/share/umu/umu.lock'...
[umu.umu_runtime:470] DEBUG: Acquired file lock '/home/sascha/.local/share/umu/umu.lock'
[umu.umu_runtime:475] DEBUG: Released file lock '/home/sascha/.local/share/umu/umu.lock'
[umu.umu_runtime:370] INFO: steamrt3 is up to date
[umu.umu_run:910] DEBUG: WINEPREFIX=/home/sascha/Games/ubisoft-connect
[umu.umu_run:910] DEBUG: GAMEID=umu-default
[umu.umu_run:910] DEBUG: PROTON_CRASH_REPORT_DIR=/tmp/umu_crashreports
[umu.umu_run:910] DEBUG: PROTONPATH=/home/sascha/.local/share/lutris/runners/proton/ge-proton
[umu.umu_run:910] DEBUG: STEAM_COMPAT_APP_ID=default
[umu.umu_run:910] DEBUG: STEAM_COMPAT_TOOL_PATHS=/home/sascha/.local/share/lutris/runners/proton/ge-proton:/home/sascha/.local/share/umu/steamrt3
[umu.umu_run:910] DEBUG: STEAM_COMPAT_LIBRARY_PATHS=/home
[umu.umu_run:910] DEBUG: STEAM_COMPAT_MOUNTS=/home/sascha/.local/share/lutris/runners/proton/ge-proton:/home/sascha/.local/share/umu/steamrt3
[umu.umu_run:910] DEBUG: STEAM_COMPAT_INSTALL_PATH=/home/sascha/Games/ubisoft-connect/drive_c/Program Files (x86)/Ubisoft/Ubisoft Game Launcher
[umu.umu_run:910] DEBUG: STEAM_COMPAT_CLIENT_INSTALL_PATH=
[umu.umu_run:910] DEBUG: STEAM_COMPAT_DATA_PATH=/home/sascha/Games/ubisoft-connect
[umu.umu_run:910] DEBUG: STEAM_COMPAT_SHADER_PATH=/home/sascha/Games/ubisoft-connect/shadercache
[umu.umu_run:910] DEBUG: FONTCONFIG_PATH=
[umu.umu_run:910] DEBUG: EXE=/home/sascha/Games/ubisoft-connect/drive_c/Program Files (x86)/Ubisoft/Ubisoft Game Launcher/UbisoftConnect.exe
[umu.umu_run:910] DEBUG: SteamAppId=default
[umu.umu_run:910] DEBUG: SteamGameId=default
[umu.umu_run:910] DEBUG: STEAM_RUNTIME_LIBRARY_PATH=/usr/lib:/usr/lib32:/usr/lib/libfakeroot:/home/sascha/.local/share/lutris/runtime/Ubuntu-18.04-i686:/home/sascha/.local/share/lutris/runtime/steam/i386/lib/i386-linux-gnu:/home/sascha/.local/share/lutris/runtime/steam/i386/usr/lib/i386-linux-gnu:/home/sascha/.local/share/lutris/runtime/steam/amd64/usr/lib:/home/sascha/.local/share/lutris/runtime/steam/amd64/usr/lib/x86_64-linux-gnu:/home/sascha/.local/share/lutris/runtime/Ubuntu-18.04-x86_64:/home/sascha/.local/share/lutris/runtime/steam/i386/usr/lib:/home/sascha/Games/ubisoft-connect/drive_c/Program Files (x86)/Ubisoft/Ubisoft Game Launcher:/usr/lib64:/home/sascha/.local/share/lutris/runtime/steam/amd64/lib/x86_64-linux-gnu:/home/sascha/.local/share/lutris/runners/proton/ge-proton/files/lib:/home/sascha/.local/share/lutris/runtime/steam/i386/lib:/home/sascha/.local/share/lutris/runtime/steam/amd64/lib
[umu.umu_run:910] DEBUG: STORE=none
[umu.umu_run:910] DEBUG: PROTON_VERB=waitforexitandrun
[umu.umu_run:910] DEBUG: UMU_ID=umu-default
[umu.umu_run:910] DEBUG: UMU_ZENITY=
[umu.umu_run:910] DEBUG: UMU_NO_RUNTIME=
[umu.umu_run:910] DEBUG: UMU_RUNTIME_UPDATE=
[umu.umu_run:910] DEBUG: UMU_NO_PROTON=
[umu.umu_run:910] DEBUG: RUNTIMEPATH=/home/sascha/.local/share/umu/steamrt3
[umu.umu_run:910] DEBUG: UMU_STEAM_GAME_ID=
[umu.umu_run:910] DEBUG: UMU_INVOCATION_ID=dc2105213f29477fd96012580a8cbf78
[umu.umu_run:921] DEBUG: (PosixPath('/home/sascha/.local/share/umu/steamrt3/umu'), '--verb', 'waitforexitandrun', '--', PosixPath('/home/sascha/.local/share/umu/umu-shim'), PosixPath('/home/sascha/.local/share/lutris/runners/proton/ge-proton/proton'), 'waitforexitandrun', '/home/sascha/Games/ubisoft-connect/drive_c/Program Files (x86)/Ubisoft/Ubisoft Game Launcher/UbisoftConnect.exe')
[umu.umu_run:664] DEBUG: prctl PR_SET_CHILD_SUBREAPER exited with status: 0
ProtonFixes[14637] WARN: [CONFIG]: Parent directory "/home/sascha/.config/protonfixes" does not exist. Abort.
Traceback (most recent call last):
  File "/home/sascha/.local/share/lutris/runners/proton/ge-proton/proton", line 2179, in <module>
    protonfixes.setup_mount_drives(setup_dir_drive)
  File "/home/sascha/.local/share/lutris/runners/proton/ge-proton/protonfixes/__init__.py", line 102, in setup_mount_drives
    if os.path.exists(directory) and not _is_directory_empty(directory):
  File "/home/sascha/.local/share/lutris/runners/proton/ge-proton/protonfixes/__init__.py", line 88, in _is_directory_empty
    return not any(os.scandir(dir_path))
PermissionError: [Errno 13] Permission denied: '/mnt'
[umu.umu_run:681] DEBUG: Child 14528 exited with wait status: 256
[umu.umu_run:683] INFO: [Errno 10] No child processes
Monitored process exited.
Initial process has exited (return code: 0)
All processes have quit
Exit with return code 0
DEBUG    2025-08-26 09:44:13,967 [monitored_command.on_stop:232]:Process 14510 has terminated with code 0
DEBUG    2025-08-26 09:44:15,219 [game.beat:910]:Game thread stopped
WARNING  2025-08-26 09:44:15,219 [game.on_game_quit:948]:Game still running (state: running)
INFO     2025-08-26 09:44:15,219 [game.stop:921]:Stopping Ubisoft Connect (wine)
DEBUG    2025-08-26 09:44:15,219 [game.stop_game:877]:Ubisoft Connect (wine) has run for 2 seconds
WARNING  2025-08-26 09:44:15,219 [game.stop_game:879]:The game has run for a very short time, did it crash?
DEBUG    2025-08-26 09:44:15,220 [game.stop_game:889]:Playtime: 1 minute
DEBUG    2025-08-26 09:44:15,220 [game.on_game_quit:966]:Ubisoft Connect stopped at Di, 26 Aug 2025 09:44:15
DEBUG    2025-08-26 09:44:15,245 [application.on_game_stopped:791]:Removing 57 from running IDs
DEBUG    2025-08-26 09:44:15,263 [path_cache.add_to_path_cache:47]:Adding Ubisoft Connect (wine) to path cache

No error occurs either. I click on Start/Play, Lutris minimizes itself, as I have set it to do so. Then it takes a few seconds and Lutris maximizes itself again.

PermissionError: [Errno 13] Permission denied: '/mnt'

You don’t have permission to access /mnt directory

Oh ok. And what do I need to do to fix that?