I've heard that it can be caused by not having PhysX installed.
PhysX installed automatically, just to make sure I have updated one of the computers to later version.
No difference though.
The Stack Violation is caused by the needed game server not being available for you to connect to and play on.
I have not heard before, but I had the problem from yesterday on and the whole day today. You sure that can cause such behavior.
Anyhow, Thank you booth for your ideas. Maybe Cyan has an idea as well.