With the amount of things you have tried and nothing works, its because
something is wrong with one of the video files (Event) you have on the
timeline that’s causing the problem (probably corrupted or something).
You probably can identify the culprit, which would be the clip the preview
window turns red and error pops up….. Try deleting or replace it and
see what happens.
Steve Rhoden (Cow Leader)
Film Maker & VFX Artist.
Owner of Filmex Creative Media.
Samples of my Work and Company can be seen here:
https://www.facebook.com/FilmexCreativeMedia