Lets start with:
Server Info
As all Clients are unable to join there is no info in Hardware, Clients use steam Version, but even on "unzipped" clients the following happens:Problem in short
Long story
Unfortunately i cannot provide the logs of the "initial Crash", but thats not the matter. I built up Server from zip again, same with Client. Unable to join. When i remember correct on first join i was asked for the credentials (Name & pass) to my account. When i join now with fresh Client it only asks for username.If other Information could be of use let me know, i try to provide. savegame is 24mb, not sure if Forum can handle.