Lutris Not Launching EXE game files

When I try to open a game, it shows ‘NoneType’ object has no attribute ‘lower’. How do I fix it? Due to this I couldn’t able to run any windows EXE game files

does this happen with every game?

more details here would help, the NoneType error implies there’s a string somewhere that isn’t being set, but without context that could mean pretty much anything