Youtube: Flash or Quicktime suddenly required

[Tourgott]

Hello guys, could anybody please explain why I'm suddenly (since 2 days) getting above mentioned error whenever I'd like to watch a video on Youtube? I never had Flash or Quicktime installed (clean out of the box Yosemite installation) just with two Safari extensions: Adblock + Clicktoplugin. YT worked like a charm and I don't want to install Flash or Quicktime.

Thanks in advance

Edit - Just realized that Quicktime is built-in in OS X. I guess that's why YT worked without Flash which is good. But why is it suddenly not working anymore? Nobody else got this problem?

Edit2 - Ok, it has to do with Clicktoplugin. I'm not sure why but when I disable the plugin, youtube works. Hm...

 

[GlenK]

I'm having dark screen issues with YouTube. Just started last week. Audio comes through but video is dark screen. Don't know if it's a flash/quicktime issue or not.

Only having issues on MBP.

 

[WrrN]

I set my YT video watching prefs to HTML5 and have not turned back ... https://www.youtube.com/html5