Well, I somehow fixed the initial problem, but don't know what I did. But, now all the video clips in video track 1 are greyed out and don't show on playback of the video. Audio plays ok but no video. Also, text tracks on video track 2 do not show on playback.
I downloaded VideoPad and reinstalled, but that didn't help. Closed the file, opened VP, cleared the cache folder, then opened video. No help.
This maybe a simple problem, but I've never seen it before. I've been using VP for several years.