If any of the video's on YouTube were made with Java or FlashPlayer they will NO LONGER work in Chrome. Chrome stopped support for all NPAPI plugins https://support.google.com/chrome/answer/6213033 This prevents Java, FlashPlayer, Silverlight and Unity from working. I have a few game sites I use and I had to reload a new version of IE just to play them. They recommend either FireFox or IE11.

They say they'res a workaround but it's AT YOUR OWN RISK!!! and could really screw up your machine.