C2 will close the project, and will "freeze" with no kind of message.
And if I go the task manager, then on display of the manager appears the default window message "C2 has stopped working".
Same with me, it happens to me randomly maybe 70% of the time. It feels like its time based, if you don't do much and close C2 it will be fine but once you've been using it for ages it will stop working on exit.