I have the same problem since yesterday (Windows 10). I even installed the whole game fresh, without any change, still says "Network error" when the game tries to log in :(

i opened up a bug report in their bugtracker system some days ago.

http://old.neocoregames.com/mantisbt/view.php?id=2104

i did some research and it seems that its a dead route on reaching the login-server.

They may or may not be working on the issue. I can't tell because they are officially ignoring the issue. It happenes in their other games aswell.

So feel free to complain. I'm at your side. Just make sure the Threads don't vanish and the word spreads.