Hi. You said you tried what I said. Let's try it a different way.
When you have a youtube green screen, right click on the screen and uncheck hardware acceleration. Click close.
Option 2
When utube video showing green, right click on the (cog) bottom of video, click quality and drop the quality to 360.
What shows now?
Install this codec pack as well.
http://filehippo.com/download_klite_codec_pack/tech/13319/