Opened a project in Movie Edit Pro Premium - everything seemed normal - images on timeline clips and on monitor. Decided to close without editing and start a new project and loaded an Mp4 clip - just a black/blank thumbnail on the track. Tried a .mts file - same thing except the thumbnail had a corrupted image - just vertical lines on the thumbnail - nothing at all in the playback window, save a flickering line at the base of the viewer. Audio seemed OK. Altered a few settings in Program settings - unchecked and checked Hardware acceleration playback, Hardware encoding export. Multiple restarts - just nothing. Did a program re-set - still nothing. I recently upgraded windows 7 to 10. Graphics card is NVIDIA GeForce GTX 650. PC is I7 processor, 16 Gb RAM. Any ideas please?