Not working right now. Get a blank screen clicking on extension (https://i.imgur.com/sw66MFd.png), clicking on options brings a new tab with 5 buttons and none of them do anything now. Please stop replying to reviews saying "it's fine", you have a variety of people reporting it's clearly not and you should know youtube's been cracking down on this sort of thing. (edit: firefox current version)
This happens when either the extension files get corrupted, or you are using a fork of Firefox with extension storage disabled
Try going to about:config and making sure webextensions.storage.sync.enabled is set to true. If it already is, try uninstalling, restarting your browser, and reinstalling
