Earlier today, I rebooted my PC and after logon I was presented with an Adobe Flash update, which I ran and then forgot about it. This evening whilst catching up on the various highlights (I use the term loosely) of Saturday TV, I noticed my videos regardless of source all had a green bar across the top.
I am not sure what the new version of flash has done to my computer but to resolve the issue I had to disable hardware acceleration.
Right Click on the Video, select Settings
and untick the box.
Select Close and refresh the video.
The green bar has now gone and the picture is clearer too.
Hope this helps.