Celluloid and VLC does not play anymore video, the sound is fine but the video is black, (Celluloid won't even start when I double on a video, I just got a spinning wheel for a while and nothing is happening)
This happens only on my account/session, on the others accounts (my kids) all players work just fine.
I started VLC in terminal with "vlc -vvv" and I get this
Thank you @mendy , I did put at "video output" XVideo like written on the last post of your link and this solved the problem for VLC (x11 works as well, many other options, I will fine tune later on).
Again thanks a lot.