Goody2Shoes

I can't play on a friends server. I can actually log in, but I only see the 'forest intro screen'. I seem to be able to move and interact with the things around me, but I am basically 'blind'. I can see my HUD and according to my nav I am moving and I get XP and loot from 'randomly' hitting stuff. The error I am getting ist (unfortunatly in german): "EAC: Verletzung der Integrität Unknown file version (7DaysTo Die_Data\resources.assets.ress) Du wirst während der Spielsitzung nicht auf durch EAC geschützte SErver zugreifen können" I was able to play with my friends before on the same server. I am still able to play on my own server. Please help.