That's a plug-in error. Since it mentions the OpenCV framework and optical flow stuff, we could assume that it's The Foundry's Kronos, but we can't be sure of it. As Mr. Adobe said, you need to provide more info - a lot more.
thank you for your help, it was a problem with the mb denoiser II, i had to delete it and load it back again, and done!! No more crash!! Thanks!!!