Thanks for getting back to me. 1. I went from OS X Mojave to Catalina. 2. The VOB files are original to the content that I was trying to view. 3. No I haven't tried VLC media player. 4. No I haven't downloaded any VOB conversion software. At this time the subject is moot in that my Mac suffered a display failure and I have one on order along with, a logic board(going from 2.8 GHz to 3.06 GHz), a used upper and lower case, trackpad, speakers, and lower hinges (on upper case) for the display. I am considering once I have the Mac back together, of revering back to my original OS X El Capitan, and starting the upgrade process over. As I am retired from working in healthcare for45years, I don't have an active need for a Mac so long as my Windows Surface works. It then is something to occupy my time. But thanks for your being on this forum as a person who can give advice.