Left 4 Dead not launching on Steam with Proton 8.0
I'm new to Linux, using Kubuntu. I got Left 4 Dead 1 installed from Steam and I'm using Proton 8.0. I get an error saying "An error occurred while launching this game: invalid app configuration". Is there a launch option I should be using? Something else?
That's weird, Half Life 2 had a Linux version noted in Steam and it runs fine. L4D didn't have a Linux version noted and it didn't give me the option to install it until I selected Proton. I don't know, I'm very new to gaming on Linux so its probably user error.