Steamrt4/toolmanifest.vdf - Initial process has exited (return code: 256)

General Discussion
1

Issue

FileNotFoundError: [Errno 2] No such file or directory: '/home/leetran/.local/share/umu/steamrt4/toolmanifest.vdf'                                                                                                 
  Monitored process exited.                                                                                                                                                                                          
  Initial process has exited (return code: 256)                                                                                                                                                                      
  All processes have quit                                                                                                                                                                                            
  Exit with return code 256

Root Cause

  The ~/.local/share/umu/steamrt4/ directory existed but was empty — the Steam runtime download had failed or was interrupted, leaving no files (especially toolmanifest.vdf). When umu tried to build the Proton →
  steamrt4 → host command chain, it couldn't find toolmanifest.vdf and crashed.

  Additionally, Steam's CDN is currently returning errors for the latest-public-beta symlink endpoint (Error 118), which prevents umu from automatically re-downloading the runtime.

Fix Applied


  1. Removed the empty steamrt4 directory — so umu wouldn't see a corrupted partial install
  2. Manually downloaded and extracted the steamrt4 runtime from https://repo.steampowered.com/steamrt4/images/4.0.20260714.251823/SteamLinuxRuntime_4.tar.xz (SHA256 verified)
  3. Installed it to ~/.local/share/umu/steamrt4/ — the correct location umu expects

  The runtime now validates successfully (mtree is OK) and GE-Proton11-1 launches correctly through the steamrt4 → host chain.
2 Likes
2

Worked perfectly. Thank you.

1 Like