Interesting snippet from steam log:
4062.791:0008:0009:trace:module:load_dll Found L"C:\\windows\\system32\\opengl32.dll" for L"Opengl32.dll" at 0x7a820000, count=2
4062.791:0008:0009:trace:module:GetModuleFileNameW L"C:\\windows\\system32\\opengl32.dll"
OpenGL provider: Opengl32.dll
com.maddox.opengl.GLContextException: ScreenMode NOT changed
at com.maddox.il2.engine.Config.createGlContext(Config.java:542)
at com.maddox.il2.engine.Config.createGlContext(Config.java:595)
at com.maddox.il2.game.Main3D.beginApp(Main3D.java:507)
at com.maddox.il2.game.MainWin3D.beginApp(MainWin3D.java:212)
at com.maddox.il2.game.Main.exec(Main.java:422)
at com.maddox.il2.game.GameWin3D.main(GameWin3D.java:235)
java.lang.NullPointerException
at com.maddox.rts.CfgTools.save(CfgTools.java:59)
at com.maddox.sound.AudioDevice.saveControls(AudioDevice.java:385)
at com.maddox.il2.engine.Config.saveSound(Config.java:484)
at com.maddox.il2.engine.Config.save(Config.java:299)
at com.maddox.il2.game.MainWin3D.endApp(MainWin3D.java:168)
at com.maddox.il2.game.Main.exec(Main.java:451)
at com.maddox.il2.game.GameWin3D.main(GameWin3D.java:235)
I've fixed it by uninstalling Il-2, and manually removing leftover directory .steam/steam/steamapps/common/IL 2 Sturmovik 1946. It launches now!
Maybe I've changed some settings in the way it made it to break?
I believe I've accidentally selected 1920x1080x16 mode instead of 1920x1080x32, as I managed to break it again... So it's not the Proton issue.
opengl32.dllx1 2019-03
Compatibility Report
System Information
I confirm:
steam-15320.log
Symptoms
Game stopped working after some recent Debian Sid ugprades. Other native game SOMA works OK, and Il-2 worked OK too some time ago. Now it just doesn't start. Console shows this:
Basically, game window does not appear.
No difference if I start using "optirun" to enable discrete NVIDIA card (as I always do), or without (using Intel graphics).
Reproduction
Just click Play in Steam app.