If the game is launched offline, during the initial startup script extender will give an error about updates. With the way steam deck handles multiple windows the error is impossible to click away. This error causes the game to not load into the main menu. If you force the error to close by using the decks window manager it causes the entire game to close too.
orbitaldr0p
commented
1 year ago 
The error in question.
Operating System
Linux
Extender Version
v55
Game Version
v3.6.117.3735
Bug Summary
If the game is launched offline, during the initial startup script extender will give an error about updates. With the way steam deck handles multiple windows the error is impossible to click away. This error causes the game to not load into the main menu. If you force the error to close by using the decks window manager it causes the entire game to close too.
Links
No response