Cannot launch the game on Steam on Win11 after hotfix

[Toxophilix]

Fix that worked for me on CachyOS

Error: Grim Dawn requires Steam. Please launch the application from the Steam interface

CachyOS here - same issue as everyone else. The only thing that worked for me was to close Steam, install ProtonUp-QT, then install Proton GE 11-3 through that interface for Steam. I then restarted Steam, selected Proton GE 11-3 as the forced compatibility layer in Grim Dawn’s compatibility settings.