I am running Photo Mechanic Version 5.0, build 19695 (4a8c3fe) on a Mac with OS X 10.13.5. I have been shooting 4K video lately and while I used to see thumbnail images for these files, now I see black frames with the message, "unable to render image." The video files are 4K .mov files with H.265 compression. They are typically about 5 gb in size. Is there something I can do to fix this? Thank you very much.