Constant Buffer Overflow when pausing the game in the background for a while.

Not 100% sure how long, but if I pause in single player for a long time (1-2 hours) and tab back into the game, it crashed and gave me the message "Constant Buffer Overflow".

Also when relaunching and trying to load back in, I am stuck on the loading screen. It looks as though it has frozen. Mawdun Quarry is where it tried to load into.

+
occurs also after arouond 20 minutes