I've had a problem for the past couple of months where when I play a YouTube video (hard to avoid them nowadays -- many websites use YouTube to host videos), my iTunes songs freeze. I press PLAY and nothing happens. Then, when I try to play another YouTube video, it's frozen too. Basically, I'm unable to play any online video or audio track. This occurs no matter what browser i use (Chrome, Firefox, Safari). If I switch to a different browser, it's frozen too. The only cure I've figured out is to restart my computer. I've got an iMac 5k 27-inch, 2017 4.2 GHz Core i7 running High Sierra 10.13.3. Anyone else run into this problem? If so, what did you do to cure it? I've done a bunch of searches and can't find any posts for anything like this. Thanks!