MC still crashes (as with 8.6.1) when I enter into Color Correction mode on clips which have the FrameFlex "S" on it. In my case, I created an UHD-project and linked to UHD-media. For quicker editing, I then switch the project to 1080p50, and transcode the linked clips to DNxHD-240. With these media I do my editing work and export a final Full-HD movie.
If I apply color correction on the transcoded DNxHD media, MC crashes. If I switch to UHD format (3840 x 2160)/50p, color correction works fine, without crashing MC.
Joachim