I'm not very OSX savy. I have a dated Mac Mini and upgraded to High Sierra the other day. If I restart my computer youtube will play for a while. When I return, Youtube videos appear to be continuously loading. This happens if I link to a video from other sites, or go directly to Youtube. It also happens consistently in both Safari and Chrome. Vimeo vides seem to do the same thing. I installed the latest version of Adobe Flash. Have no clue what to try. Thanks much in advance.