Hi.
I have been getting this error for a long time, version 6, 7 and 8. It's random, in small or big scenes, it doesn't matter. Sometimes it happens several times on the same day, sometimes days or weeks go by without it happening. But it always happens during rendering, when trying to zoom, or display a postprocess parameter, the mouse click doesn't work, and this error appears. If I wait a while, everything goes back to normal, and everything works correctly again.