Hello @ShiroBlank, can you temporarily remove or disable mangohud and test if that has an effect? ([#6763 (comment)](https://github.com/ValveSoftware/Proton/issues/6763#issuecomment-1551704421))

Thanks for your swift reply!
After running yay -Rns mangohud to remove mangohud and all dependencies, and performing a full system shutdown and then trying once more, the games still refuse to load.
Proton Log Here: Link

I am currently experiencing the same issue. I thought my games didn't work on linux and was about to switch back to windows until in found this. I quickly switched to proton 7 and surprisingly enough, all my not-working games worked again..

I'll leave my steam system info below, as it might be helpful:
Steam system: https://pastebin.com/bgyvR73s

Same here, I tested it with the games Baba is You (this one because it's native) and Fallout New Vegas (this one with Protons only).

Starting the game natively or Proton-7.0-X works normally. Testing with Proton-8.0-X and Proton-Experimental, it says the game is running, but no game window is displayed.

Unfortunately I've uninstalled mangohud and gamemode as instructed in a different thread and it still refuses to work 😿 - I also don't have GOverlay installed.

Huzzuh! I fixed the issue!! 🎉 - I had SteamVR [Beta] branch installed and once I uninstalled it, the game booted up fine! I read through my logs and saw it complaining about vrclient.so, made a guess, and it worked!!!! Although that is rather inconvenient having to uninstall steamvr to use proton 8... - hopefully that will be fixed sooner rather then later.

I experience the same/a similar issue with Squad (did not try other games). Posted about it in the Squad issue here: https://github.com/ValveSoftware/Proton/issues/938#issuecomment-1536895405

Doom Eternal fails to launch on the AMD open-source and proprietary drivers w/ this msg Assertion failed: !status, file ../src-wine/dlls/winevulkan/loader_thunks.c, line 3043

Originally posted here.

Update - for clarification, this issue is definitely a Proton 8 regression since another user confirmed the same behavior on their system.

Also, the issue is strictly happening on the AMDVLK (open-source) and AMDGPU-PRO (proprietary) Linux drivers. RADV works on Proton 8 w/o issue.

Also, the issue is strictly happening on the AMDVLK (open-source) and AMDGPU-PRO (proprietary) Linux drivers. RADV works on Proton 8 w/o issue.

Just checked, and after switching to RADV from AMDVLK, the games that wouldn't work, start working just fine. Though I do hope this gets fixed since AMDVLK works better for me.

Huzzuh! I fixed the issue!! tada - I had SteamVR [Beta] branch installed and once I uninstalled it, the game booted up fine! I read through my logs and saw it complaining about vrclient.so, made a guess, and it worked!!!! Although that is rather inconvenient having to uninstall steamvr to use proton 8... - hopefully that will be fixed sooner rather then later.

I have non-beta SteamVR installed, it causes the same complaint and crash as well.
steam-502500.log
The beta and linux_v1.14 branches behave the same. Uninstalling allows games to boot.

Crysis Remastered, Moving Out, GTA5, GTA4, RD2, 80% of games, crash when launch game using Proton8.0 and experimental.
Proton 8 is a regression. Furthermore, the WineServer freezes when you launch Proton8 and when you try to close Steam, 10 processes are blocked, but what 20 processes can handle one execution + Python3, so on and so forth...
Please do things simply and with quality, I can understand Wine's processes, but not anything else..
Instead of optimizing you are getting worse, you have to make pipelines, to do checks on the things you do, called TESTS.

Recently I have this problem too. Proton version above 7 doesn't work, neither GE. When game using version 8, the directory in compatdata is not created.Install and start game from ext4, NTFS and BTRFS is unchanged.Install steam from steam web and install from repository, no change.
Starting steam from the terminal show this error:
/bin/sh\0-c\0/home/mxxxx/.steam/ubuntu12_32/reaper SteamLaunch AppId=324800 -- /home/mxxxxx/.steam/ubuntu12_32/steam-launch-wrapper -- '/mnt/XXXXGB/SteamLibrary/steamapps/common/SteamLinuxRuntime_sniper'/_v2-entry-point --verb=waitforexitandrun -- '/home/mxxxxx/.steam/steamapps/common/Proton 8.0'/proton waitforexitandrun '/home/mxxxxx/.steam/steamapps/common/Shadow Warrior 2/ShadowWarrior2.exe'\0
chdir "/home/mxxxxx/.steam/steamapps/common/Shadow Warrior 2"
ERROR: ld.so: object '/home/miroslav/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/home/miroslav/.steam/ubuntu12_64/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS64): ignored.
ERROR: ld.so: object '/home/miroslav/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Uploaded AppInterfaceStats to Steam

But Lutris and Proton GE 8.xxx work perfect.
Steam system information.txt

After uninstalling all proton version, runtime/soldier and deleting .acf files and reinstalling them in home folder all version worked.