On experimental Proton multiple games now fail to launch with Incompatible Platform, revert to stable fixes issue.

[warwizard55]

Compatibility Report

Steam HT-86DW-GY2C-RGBC
"In the past 24 hours an experimental Proton build was updated twice. I have previously played Terraforming Mars in desktop mode using a steam OCLD with a steam dock and an external keyboard mouse and monitor for 333 hours. Now when I attempt to launch the game I get the following popup: "An error occurred when launching this game: Invalid Platform" Testing other games... Planetbase same issue, Offworld Trading Company same issue Gary Grigsby's War in the East, same issue, Sid Meier's Civilization IV, Colonization, same issue. For the time being, let's assume that there is a change made in the proton updates in the experimental branch that has broken my usage of a steam deck as an actual desktop to play games. There is dust on the screen and all the controls as I do not use the steam deck as a game controller, I use it as a very low wattage desktop. I will change to the stable Proton branch for now. "

Changing to stable proton version and redownloading the games updates to be compatible with the stable lets me play my games as per a normal desktop

System Information

-Operating System: SteamOS 3.6.18 Build: 20241011.101
KDE Plasma Version: 5.27.10
KDE Frameworks Version: 5.115.0
Qt Version: 5.15.12
Kernel Version: 6.5.0-valve21-1-neptune-65-g33487bf05ed3 (64-bit)
Graphics Platform: X11
Processors: 8 × AMD Custom APU 0932
Memory: 14.5 GiB of RAM
Graphics Processor: AMD Radeon Graphics
Manufacturer: Valve
Product Name: Galileo
System Version: 1

• Proton version:

I confirm:

• [X ] that I haven't found an existing compatibility report for this game.
• [ X] that I have checked whether there are updates for my system available.

Symptoms

Games that were working fine prior to the latest updates and proton experimental now refuse to launch when using desktop mode with external monitor mouse and keyboard.

Reproduction:

Set up steam deck with steam docking station, external keyboard mouse and monitor, enable proton experimental version reboot and load the experimental version, and go to desktop mode, install updates for one of the games I listed above, try to launch game, see error message. Go back to game controller mode and disable use of the proton experimental , reboot, reload stable , go to desktop mode, load update for the game, launch game, it now works.

I have many games that do not work on the steam deck in desktop mode with docking station, external mouse kbd and monitor, because the game is forced to play using the controller's buttons switches and touch pads. I find that the steam deck is forcing usage of the controller mode stuff instead of allowing me to make the determination of how I want to use the steam deck. I have perhaps 50,000 hours of gaming in desktop mode, and perhaps 500 hours using a game controller. Please please please just give me a switch or configuration template that lets the game use an external keyboard mouse and monitor.

[Fuhrmaaj]

Edit: I uninstalled Proton Experimental and reinstalled it and it works now.

Warhammer 40,000: Dawn of War II - Anniversary Edition
Warhammer 40,000: Dawn of War II - Retribution

System Information

OS: Pop!_OS 22.04 LTS x86_64
Host: Z790 Pro RS
Kernel: 6.9.3-76060903-generic
Resolution: 1920x1080, 1920x1080
DE: GNOME 42.9
WM: Mutter
CPU: 13th Gen Intel i7-13700KF (24) @ 5.300GHz
GPU: AMD ATI 03:00.0 Device 747e
Memory: 31914MiB
Proton Version: Experimental

I'm not sure if this is related to the same issue, but when I first installed Pop!_OS in January of 2024, Dawn of War 2 didn't work. When Anniversary Edition was released on September 19, both Anniversary Edition and Retribution worked perfectly (but I get the popup that my distro isn't supported). I played the game on Sunday, then a new version of Proton Experimental was downloaded and now when I launch I get the same popup, then a transparent window opens, then it quits and the Play button for Dawn of War 2 appears again.

I put the following in my Launch Options:
PROTON_LOG=1 PROTON_LOG_DIR=$HOME/proton_logs %command%
But no log file is created.

I verified the integrity of the installed files. I switched to Proton 9.0-3, and the game does launch but it has a lot of graphical problems and runs very slow. Basically the game recently started working only on Proton Experimental when Anniversary Edition was launched, then an update to Experimental between October 20 and October 22 inclusive has caused it to fail to launch.