Update: I just checked my laptop and it was not running the beta channel for steam. So this might even be a GPU independent issue with publicbeta, build 1774488570

Likely the same issue for me, client 1774488570 with some games refusing to start. Stable client works fine.

Did you set any environment variable in launch option?

see
https://github.com/ValveSoftware/steam-for-linux/issues/13012#issuecomment-4131658805

Relevant logs

Please check the logs in ~/.steam/steam/logs which are likely to have more information, particularly console_log.txt and console-linux.txt. (Doesn't the issue report template ask you to attach them?)

Every time you launch a game, you should see a line logged there that looks something like this:

[2026-03-26 15:20:21] /bin/sh\0-c\0…/steam-launch-wrapper -- …/reaper SteamLaunch AppId=1118310 -- MANGOHUD=1 '…/SteamLinuxRuntime_sniper'/_v2-entry-point --verb=waitforexitandrun -- '…/RetroArch/retroarch.sh'\0

and some messages at around the same time in console-linux.txt.

As @Billli11 says, one known regression in beta 1774488570 is that if you have the Launch Options for a game set to something like MANGOHUD=1 %command%, it won't work. The workaround is to use launch options like env -- MANGOHUD=1 %command% instead. This regression is tracked in #13012.

Or, if something different has gone wrong, hopefully you'll get error messages logged when you try to launch the game that will shed more light on this.

I was playing Elden Ring this morning, and after returning from a break I noticed there was a steam client update and updated to Steam Version: 1774488570 just like the OP.

Launched Elden Ring, processes started firing, and then everything stopped with the game failing to launch.

Closed/retarted Steam... same result.

Closed steam and re-launched it via terminal to watch output.

Launched Elden Ring and BG3 and noted similar output (pasting only 1) with the same end result...
chdir "/data/steamlibrary/SteamLibrary/steamapps/common/Baldurs Gate 3/bin" ERROR: ld.so: object '/home/<uid>/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored. ERROR: ld.so: object '/home/<uid>/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored. ERROR: ld.so: object '/home/<uid>/.local/share/Steam/ubuntu12_64/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS64): ignored. Game Recording - would start recording game 1086940, but recording for this game is disabled Adding process 1686197 for gameID 1086940 pid 1686198 != 1686197, skipping destruction (fork without exec?) Game Recording - game stopped [gameid=1086940] Removing process 1686197 for gameID 1086940
I have a Framework 16 laptop with dGPU, so I do use launch options to force games to use it instead of the default iGPU.... DRI_PRIME=1 %command%

Tried @smcv suggestion and changed the Elden Ring launch options to env -- DRI_PRIME=1 %command% and the game launched successfully! Thank you for the workaround!

@DanielR-I, that is the regression described in #13012. We don't need additional reports of that regression.

What we don't yet know is whether @Gythrim is experiencing the same regression, or something different.