Per https://twitter.com/Plagman2/status/1110665993590759425 make sure you download it in "tools"
I can confirm that the problem is indeed that Steam client does not download Proton 4.2 by default, even if it is selected in the settings. I can see this in the Library -> Tools list. I can download Proton 4.2 in that list, and after that the games begin to work again.
PS:
@dlove67 Thanks, I've just managed to find this out myself. It's still a bug in the Steam client though.
@Lastique I think this would be a bug in https://github.com/ValveSoftware/steam-for-linux not proton, though.
Besides, Pierre-Loup Griffais is a "valve coder" so I think they're aware that the issue exists ;)
Fair enough, I'll close this since this is not a Proton bug.
proton 4.2x1 2019-03proton 3.16-8x1 2019-03proton 4.2-1x1 2019-03PROTON_LOG=1x1 2019-03
Compatibility Report
System Information
I confirm:
Adding
PROTON_LOG=1 %command%to the game launch options does not produce a$HOME/steam-$APPID.logfile.Symptoms
When the Proton version in the Steam setting is set to 4.2-1, no Proton-based game starts. The "Starting" window from Steam blinks for an instant and then nothing happens. When Proton 3.16-8 Beta is selected, the games start as expected. I have tried with multiple titles, "We Happy Few" for one example.
I suspect that Steam doesn't download Proton 4.2-1 runtime for some reason. There are various Proton versions in my game library folder, including 3.16 and 3.16 Beta, but there is no 4.2 folder. I tried restarting Steam client and changing the Proton version in the settings and checking for Steam client updates multiple times. Nothing helps, the Steam update says the client is at the latest version.
Reproduction