Watch out for returning to the first map !!! You will have stutters and broken missions.

[PRYSZCZYC]

If you fast travel back to the first map and then go back to Kuttenberg you will experience some stutters during the game. Additionally, the current missions will look like you are still on the first map!!! Only loading a save before going to the first map will fix the missions and get rid of the stutters in Kuttenberg.