Compatibility Report

Hello @wichyslav, please add PROTON_LOG=1 %command% to any game's launch options that you have configured to use with Proton and attach the generated $HOME/steam-$APPID.log to this issue report as a file. (Proton logs compress well if needed.)

Blind guess that you're seeing something similar to ValveSoftware/steam-runtime#312 and ValveSoftware/steam-runtime#312 (comment) might be worth trying.

I did add the launch options, but it didn't generate a log file.
Also regarding the issue you have sent, i am using a desktop and nvidia drivers are the only ones installed. I've also tried older versions of Proton, but they don't work aswell.

Same issue here, no log was generated. Proton <= 5.0-10 works fine. Here's the steam console log. The drive was at first a NTFS drive but I formatted it to btrfs because I tought that was the issue at first but nothing changed

GameAction [AppID 1118200, ActionID 23] : LaunchApp changed task to ProcessingInstallScript with ""
/mnt/hdd2/Games/SteamLibrary/steamapps/common/SteamLinuxRuntime_soldier/_v2-entry-point: line 378: /mnt/hdd2/Games/SteamLibrary/steamapps/common/SteamLinuxRuntime_soldier/pressure-vessel/bin/pressure-vessel-adverb: No such file or directory
/mnt/hdd2/Games/SteamLibrary/steamapps/common/SteamLinuxRuntime_soldier/_v2-entry-point: line 378: /mnt/hdd2/Games/SteamLibrary/steamapps/common/SteamLinuxRuntime_soldier/pressure-vessel/bin/pressure-vessel-adverb: No such file or directory
src/clientdll/installscript_posix.cpp (420) : Assertion Failed: Standalone evaluator returned error code for app 1118200
src/clientdll/installscript_posix.cpp (420) : Assertion Failed: Standalone evaluator returned error code for app 1118200
GameAction [AppID 1118200, ActionID 23] : LaunchApp changed task to SynchronizingCloud with ""
GameAction [AppID 1118200, ActionID 23] : LaunchApp changed task to SiteLicenseSeatCheckout with ""
GameAction [AppID 1118200, ActionID 23] : LaunchApp changed task to CreatingProcess with ""
GameAction [AppID 1118200, ActionID 23] : LaunchApp waiting for user response to CreatingProcess ""
GameAction [AppID 1118200, ActionID 23] : LaunchApp continues with user response "CreatingProcess"
/bin/sh\0-c\0PROTON_LOG=1 /home/fuomag9/.local/share/Steam/ubuntu12_32/../ubuntu12_32/reaper SteamLaunch AppId=1118200 -- '/mnt/hdd2/Games/SteamLibrary/steamapps/common/SteamLinuxRuntime_soldier'/_v2-entry-point --verb=waitforexitandrun -- '/mnt/hdd2/Games/SteamLibrary/steamapps/common/Proton 6.3'/proton waitforexitandrun  '/mnt/hdd2/Games/SteamLibrary/steamapps/common/People Playground/People Playground.exe'\0
Game update: AppID 1118200 "", ProcID 48511, IP 0.0.0.0:0
Starting app 1118200
>>> Adding process 48511 for game ID 1118200
GameAction [AppID 1118200, ActionID 23] : LaunchApp changed task to WaitingGameWindow with ""
ERROR: ld.so: object '/home/fuomag9/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/home/fuomag9/.local/share/Steam/ubuntu12_64/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS64): ignored.
ERROR: ld.so: object '/home/fuomag9/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/home/fuomag9/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/home/fuomag9/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
GameAction [AppID 1118200, ActionID 23] : LaunchApp changed task to Completed with ""
ERROR: ld.so: object '/home/fuomag9/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
pid 48515 != 48512, skipping destruction (fork without exec?)
ERROR: ld.so: object '/home/fuomag9/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/home/fuomag9/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
/mnt/hdd2/Games/SteamLibrary/steamapps/common/SteamLinuxRuntime_soldier/run: line 22: /mnt/hdd2/Games/SteamLibrary/steamapps/common/SteamLinuxRuntime_soldier/pressure-vessel/bin/pressure-vessel-unruntime: No such file or directory
>>> Adding process 48512 for game ID 1118200
>>> Adding process 48513 for game ID 1118200
>>> Adding process 48514 for game ID 1118200
>>> Adding process 48516 for game ID 1118200
>>> Adding process 48517 for game ID 1118200
Game removed: AppID 1118200 "", ProcID 48511 
Uploaded AppInterfaceStats to Steam
Exiting app 1118200
No cached sticky mapping in ActivateActionSet.

Edit: for anyone that may need this in my case manually deleting all the runtimes, reinstalling wine and reinstalling the soldier as well (with steam restarts in between) seems to have solved the issue for now!