Thanks for the reply!

With messed up I actually meant the original files are gone.
Have been able to use sowftware to find some but they were all corrupted by then (problably partly overwritten memory areas).
My backup plan if no other gamer has a save to use is playing it myself again until I arrive in Arx then invite my partner. I will also always regulary backup local files from now on, regardless which game it is hehe