Hello @waspennator, these look like the lines of interest from your Proton log:
Unhandled Exception:
System.TypeLoadException: Could not load type of field 'SensorInput.SensorProxy:incline' (1) due to: Could not load file or assembly 'Windows, Version=255.255.255.255, Culture=neutral, PublicKeyToken=null' or one of its dependencies.
at TheBridge.GameElements.HumanPlayer..ctor (System.IntPtr windowHandle, Microsoft.Xna.Framework.PlayerIndex playerIndex) [0x00000] in <afb8a81bde1b4e268a7a42a50deb8917>:0
at TheBridge.GameElements.GameWorld.LoadContent () [0x0008b] in <afb8a81bde1b4e268a7a42a50deb8917>:0
at Microsoft.Xna.Framework.Game.Initialize () [0x0007f] in <1c71adce385d4291bcc171aee8ef0032>:0
at TheBridge.GameElements.GameWorld.Initialize () [0x00000] in <afb8a81bde1b4e268a7a42a50deb8917>:0
at Microsoft.Xna.Framework.Game.DoInitialize () [0x0003c] in <1c71adce385d4291bcc171aee8ef0032>:0
at Microsoft.Xna.Framework.Game.Run () [0x00011] in <1c71adce385d4291bcc171aee8ef0032>:0
at TheBridge.Program.Main (System.String[] args) [0x0001a] in <afb8a81bde1b4e268a7a42a50deb8917>:0
[ERROR] FATAL UNHANDLED EXCEPTION: System.TypeLoadException: Could not load type of field 'SensorInput.SensorProxy:incline' (1) due to: Could not load file or assembly 'Windows, Version=255.255.255.255, Culture=neutral, PublicKeyToken=null' or one of its dependencies.
at TheBridge.GameElements.HumanPlayer..ctor (System.IntPtr windowHandle, Microsoft.Xna.Framework.PlayerIndex playerIndex) [0x00000] in <afb8a81bde1b4e268a7a42a50deb8917>:0
at TheBridge.GameElements.GameWorld.LoadContent () [0x0008b] in <afb8a81bde1b4e268a7a42a50deb8917>:0
at Microsoft.Xna.Framework.Game.Initialize () [0x0007f] in <1c71adce385d4291bcc171aee8ef0032>:0
at TheBridge.GameElements.GameWorld.Initialize () [0x00000] in <afb8a81bde1b4e268a7a42a50deb8917>:0
at Microsoft.Xna.Framework.Game.DoInitialize () [0x0003c] in <1c71adce385d4291bcc171aee8ef0032>:0
at Microsoft.Xna.Framework.Game.Run () [0x00011] in <1c71adce385d4291bcc171aee8ef0032>:0
Still borked as of latest proton Experimental build.
Still fails to launch with latest steamos and proton Experimental
Still a problem, should I report this to the fna github? I see xna stuff in there
Nah, it's more likely missing winmd support in Mono.
proton experimentalx3 2025-06
Compatibility Report
System Information
I confirm:
Symptoms
Game works fine with the native port, but fails to launch with proton Experimental .
steam-204240.log
Reproduction
Start the game with proton.