


I observed no issues with the game after a couple of hours of playing. Works out of the box with zero tinkering. Kingdom Under Fire: Heroes appears to be suffering from some sort of save game issue (I don't own the game myself) but I did not experience that with Crusaders.
Everything is black on newer Proton version. 6.XX fixes that, but controls no working.
Booted up fine with a simple launcher. I increased shadow map size but everything ran fine out of box.
fullscreen went off-screen
The game work without tweak
Works with Proton version 6.3-2.
Would not detect xbox 360 controller.

Launcher works fine! Game crashes before being able to be play on via wine.
GOG

Game launches, controller works. can navigate the menus, application crashes upon trying to start a new game.
Error: EXCEPTION_ACCESS_VIOLATION !!! KUFC CRASHED !!! Would you like to send your crash report for investigation?

Was unable to start the game with Proton 3, 4, or 5
Proton 5.0.3 can launch the configuration tool. All available versions of Proton receive a SysInitFailed error window followed by a game crash. With Proton 5.0 another error window popped up saying DXVA2CreateDirect3DDeviceManager9 failed followed by the same SysInitFailed error and a game crash.