Broken Styles Please Help!

I changed the style to dark after installing on a new pc, but that left the tables window completely white with white text, making it completely unreadable. After trying to change the individual colors nothing changed, as well as trying other color schemes. I have also fresh reinstalled heidi many times now with no changes.

Your session setting has a white background color. Change it "None" ("Ohne" in German):

Thanks that fixed it!