protonscr

Fix fullscreen games crashing when focus is lost

protonopen
ValveSoftware/Proton#8797 · opened 2025-06-11 by OilFreak · updated 2025-06-12 · 1 comments · github
OOilFreak 2025-06-11 github

Fix certain fullscreen games crashing when focus is lost (i.e. alt-tabbing)

I confirm:

  • that I haven't found another request for this feature.
  • that I have checked whether there are updates for my system available that
    contain this feature already.

I'm going to cite Fallout 3 and Touhou: Mountain of Faith specifically because those are the games I play where I've noticed this. Prior to a recent Proton update, these games would allow focus loss and regain (i.e. Alt-Tabbing) and function just fine. Now however, the games will crash when attempting to do this.
As I understand, this is normal behavior. Both games have engine limitations that cause this to happen 100% of the time on Windows. This didn't happen before on Proton and I'd have to assume that whatever update caused this change actually made Proton more accurate. However, I rather enjoyed this extra bonus of using Proton and would like to see some form of official implementation.

Kkisak-valve maintainer 2025-06-12 github

Hello @OilFreak, this needs to be evaluated on a per-game basis. Please add a note to either #2069 or #370 depending on which variant of Fallout you have along with the newest unaffected Proton version and the nearest regressed Proton version. Also, please include a Proton log of the regression.

For the Touhou game, it doesn't appear there's an open compatibility report for that game. Please grab the compatibility report template from https://github.com/ValveSoftware/Proton/issues/new?template=compatibility-report.md, copy it here, and fill it out the details and we'll track how that game is behaving with Proton here.

Nothing extracted yet.