Compatibility Report

• Name of the game with compatibility issues: Left 4 Dead 2
• Steam AppID of the game: 550

System Information

• GPU: RTX 4060 TI
• Video driver version: nvidia 550
• Kernel version: 6.9.3-76060903-generic
• steam-550.log
• System Information
• Steam Runtime Diagnostics
• Proton version: Experimental, 9.0-2

I confirm:

• [x] that I haven't found an existing compatibility report for this game.
  • There is, but it's another issue that needs to be fixed
• [x] that I have checked whether there are updates for my system available.

Symptoms

After the latest update (of Jun 25th), the game crashes when taking control over character, such as end of map intro, or taking over a bot. The game then game freezes and then closes after ~3 seconds. I did see a discussion comment stating that it does not crash when playing as the infected in versus, but I have not tested that.

The game was running fantastically before the update, with proton. Now it's unplayable

Video of loading c1m1_hotel, I stopped it the moment it began crashing
https://github.com/ValveSoftware/Proton/assets/4030546/cb25dac2-91af-4d8b-8d52-67ce3a5408f4

Reproduction

1. Launch any map, such as map c4m1_milltown_a
2. Wait for the map intro scene to end
3. Crash

Other Information

This seems to be a proton issue, as the mess of a native build does not crash.
This also happens with no addons, on singleplayer and community servers, and with -safe
I wasn't sure if this should be filed here or Source-1-Games, I can post it there if need be.