The problem is pretty simple.
I've a page loading several youtube video. The loading is working fine.
When I play a video, all is ok.
I'll play another video : all is ok, the video is played.
I choose to open in full screen a video (no matter the video) : all is ok, i'm into the full screen mode.
I go back to my page because I unselect full screen mode.
And I've this error message visible into the screen shot.
How can I solve that ? Thanks in advance for your help