When trying to display vids (mp4, mkv, etc) in viewer, many times I only get a black screen. This may happen for several vids in a row until I find one that will play. Once I find one that will play, if I go back to the others that were not playing moments ago, they will suddenly begin playing correctly.
I noticed this a 2-3 months ago and tried to solve it by installing a different codec pack. I initially thought that solved the problem but the problem persists. I thought it was just certain vids but from moment to moment or day to day the same files will intermittently play correctly or not.
I was using 12.8 until upgrading to 12.10 yesterday in hopes of solving the problem... but again, it persists.
Any ideas on how to solve this would be greatly appreciated.