It's now six-months since the Developer acknowledged the changes made by YouTube, and promised a fix. A further message again promising a fix was posted in October. Hollow promises.

Given there are now decent alternatives available that work perfectly well, including 720p, it's unlikely this utility will be updated again and is now 'dead in the water'.

Sorry Dishita, but leaving users hanging for over six-months with a product that no longer works along with unfulfilled promises is wholly unacceptable.

Users at this stage now need to report the add-on to Mozilla, and have them remove it. It's little more than taking money under false pretences.