It looks like Gothic ran out of virtual memory. Have you installed any texture mods? Have you tried lowering texture quality in-game?

An old Watch post with some hacks that could help you.

I would usually recommend you get more RAM, but 1) I don't know if G3 allows access to more than 2gb and 2) I don't know if you're running Win7 32 or 64bit.

Hope this helped a little!