We've had a rash of "Congo has unexpectedly shut down" errors this week. It appears to be triggered by moving the dynamic effects tab from one screen to another, but does not necessarily occur when dynamic effects are actually running. A reboot is required to recover. We're still running 6.0.3 beta 67, which has been pretty stable for us. I didn't notice this as a fixed or still to be resolved problem in the 6.0.4 release notes.