If you are watching a video that is part of my www.ARTandSUCCESS.com site or one of my courses, it may be due to a browser setting. Aside from restarting your computer and trying a different browser, here is what student found when her video stopped playing on the Chrome Browser:
"I discovered the problem and thought I'd pass it on just in case there is anyone else that has a similar problem.
It has to do with settings in Chrome. Automatically Chrome is set to use acceleration in playing back videos embedded in sites like yours. To change this, go to Settings > Advanced > System and DE-select the 'use hardware acceleration when available'
Problem fixed!