Full-screen broken in Firefox

[guido4000]

Full-screen does not work in Firefox 41.01. OSX

Console error message:

Request for full-screen was denied because Element.mozRequestFullScreen() was not called from inside a short running user-generated event handler.

[thyrgle]

Also doesn't work in Chrome.

Version 46.0.2490.80 (64-bit) (OSX)