Can't play anylonger... Your Gamefile do not match the Server's

Hi,

somehow I can't play this game anylonger. Errormessage is this:
Image may be NSFW.
Clik here to view.

Things I tried to get arround :
Drop C:\Users\xxx\AppData\Roaming\Natural Selection 2\Workshop
Removed all Abonnements of Workshop items
Delete C:\Users\Veruhl\AppData\Roaming\Natural Selection 2
Complete Reinstall NS 2... more than once.

I don't know what happend but the Game worked fine since the last update and I've got more than 300h fun to play it.
One thing that is stange to me : after reinstalling NS2 I can play exactly 1 Game... than I have to reinstall again...
but it is no sollution for me to download 4 GB of data just to play this...

Oh btw. I can't play on Public Servers and I can't play in Training Mode against Bots... both the same error Message

Here is my current log

Can someone please help me with this ?

Thx.

moved to tech support -Kouji San