Support Can't Favorite/Like Youtube Videos in Firefox

Every time I try to add a video to a playlist, I get a message saying "Invalid Request"

When I try to Like or Dislike the video, I get a message saying "This feature is not available right now. Please try again later."

Any way I could fix this? I can do all these things in Chrome, but Firefox is my primary browser, so I'd rather not have to use a separate one just for Youtube.

EDIT: WELL I just figured out the problem is one of my add-ons. Disabled it, and things are back to normal. You guys can go ahead and close this.