Solved: rebuilt and updated system, D4 works reliably now, no crashes.
Diablo 4 regularly crashes soon after startup. It can crash at different times - sometimes during the intro cinematic, other times in the character creation/selection screen. I haven’t gotten far enough yet to create a character and load into the game world, it always crashes before that.
WoW and Diablo3 work fine on this config, just not D4. I installed D4 into the same BattleNet instance as WoW and D3, but D4 crashes frequently.
I tried changing this BattleNet instance’s Lutris profile to use lutris-GE-Proton8-5-x86_64 and VKD3D 2.8. WoW and D3 both work fine with that config, but D4 does not. Also tried lutris-GE-Proton8-7-x86_64 but no luck, still crashing.
Set all graphics options to Off or Low.
Disabled Cross-Network Play and Cross-Network Communication
Was hoping that disabling those settings would isolate the problem, but no luck, still crashes frequently even with minimal gfx, sound, and network.
lutris -d output: Ubuntu Pastebin (covers Lutris start, BattleNet start, D4 start, D4 crash, BattleNet shutdown, Lutris shutdown)
lutris --system-report output: Ubuntu Pastebin