

Unfortunately doesn’t work for me.
I launch Unity Mod Manger with mono ./UnityModManager.exe but I also tried it on Kate, both with the commandline and the Menu-Editor shown in the last post.
Both Unity Mod Manager and Kate launch, but do not change how they look.






Right, I confirmed UnityModManager looks different when I change the GTK theme.
Then, instead of Kate, I tried changing the GTK theme like you showed in Lutris and that works.
So the issue seems to lie with Mono. I found this old issue https://github.com/mono/mono/issues/9998 Mono seems to ignore the GTK_THEME environment variable. However there is a workaround:
GTK_DATA_PREFIX= mono ./UnityModManager.exemakes mono default to a classic window theme.Thanks for your help!