Greasy Fork

Seems your script don't like the old Greasemonkey v.3.17?

When i use it , your script break the YouTube interface and i see only the player and the "skelton" design.

With Tampermonkey:
That's good.

Waterfox Classic
Greasemonkey v.3.17 or Tampermonkey

This script is based on Tampermonkey, I didn't test it on Greasemonkey.

I try to find out what's wrong with Greasemonkey.

Sorry, It doesn't support Greasemonkey. This script uses lots of Tampermonkey API that Greasemonkey doesn't support.

thanks for your fast reply...
:-)