Thanks for the quick answer Vendor! Great news: I finally figured out how to make the game work after two days. I normally install games on an external hard drive (F) in order not to burden my C-drive. Apparently, SHIII doesn't like that. I had the bright idea to intall the game in the default folder and it works now.
I find this pretty annoying, since I don't like to install games on my internal hard drive and I really hesitate to burden it even more with rather heavy mods like GWX3. If anyone would know a way to by-pass these restrictions that SH3 seem to have, then I would be glad to try them out. Games normally work fine when I install them on a location that I choose myself. Anyway, I'm off to the Atlantic ocean now
