Title says it all.
I played around with the chat resizing function, then I probably double-clicked on the edge and - poof - chat is gone, video scales to the right edge of the screen.
This is not another addon interfering - I had this setup work for me before, no updates were recieved today.
I have no AV software either.
I cleaned all my cache. I am NOT going to clear all my cookies.
My browser is Firefox 40.0.2. No JS console messages - everything is “working”.
Edit: obviously enough, when I disable/uninstall the addon, chat does appear.
That’s it.
Also I probably wouldn’t need to post here if your addon had “restore defaults” button. Please add it, it’s pretty ridiculous that there is no such thing.