Was working great then today had a message pop-up on Firefox saying: some add-ons have been disabled, the following add-ons have not been verified by use in Firefox. Whilst it didn't actually show any add-ons after the message, I did notice that the Pinterest add-on was suddenly missing. And like everyone else, I get a connection error when trying to download it, despite my internet connection working just fine. Clearly someone's done something to introduce a major bug!