FCPX 10.4.2 "not responding"
I recently updated FCPX to 10.4.2 and updated High Sierra to 10.13.4. I imported my video from DV tapes 1080i (as I have done for years with FCP). The thumbnails took an extra long time to complete and some have green segments blocked out. When I press the spacebar to play the thumbnail, I get the "rotating ball". My Activity Monitor says FCPX "not responding". I have an iMac with i5 processor and 20GB RAM. I tried a different computer with an i7 processor, same result. I tried a different external HD, same result. I tried a different internal HD, same result. I tried iMovie, same result. Is the newest version of High Sierra not compatible with FCPX?
iMac, macOS High Sierra (10.13.4)