Unable to connect to session [PC]

[Skroting]

I connected to several sessions today, but suddenly I couldn't connect to any of them anymore. I didn't do anything that should trigger this error. I was just browsing through the servers trying to find one with an imminent race when I came across one to which I couldn't connect. I thought it was just that one, but I couldn't connect to the next one, or any after that. If I try to connect to "Quick match", then it's loading for a few seconds before I'm asked if I want to start a new session. I tried restarting the game, but I still get the same error. What could be wrong? I'm obviously online since I'm on the same PC right now.

http://skroting.net/images/Grid-error.jpg