6 months ago - prismaticmarcus - Direct link
Moved to Tech Support  
6 months ago - AndrewT - Direct link
This is a known issue at present, on Linux only.

Disconnect the computer from the internet then start the game. Once it is up and running, you can reconnect it again.

I assume they'll have a fix for that out soon!  
6 months ago - AndrewT - Direct link
MrLelito said: But that means that those games I start this way are not suitable for the achievements, right?
As i understand it, if you reconnect while in the main game menu, THEN start a game, you'll be okay in that respect.