Those who have already started playing G3 Forsaken Gods have certainly seen how "unpolished" it was.
Two patches have been released. I strongly suggest you to install them both :
1. Release patch (v 1.04) :Link
2. Patch 1.06 :Link
This one resolves a very serious bug in a main quest ( "Marc quest" ) that made the player get stuck in the main quest (I was...).
Be careful, these two patches will perhaps look for a wrong installation folder and won't want to install.
Just choose your correct Program Files folder and it will be OK.
In my case, they looked for a
"C:\Program Files\JoWood\Gothic III - Forsaken Gods"
I changed it to my correct installation folder :
"C:\Program Files\JoWood\Gothic 3 - Forsaken Gods"
And both installed themselves without trouble.
Good luck, and have fun.