The Add-on doesn't work any more Rated 5 out of 5 stars

OK, so this was once good.Over the last few weeks, this isn't working right any more. There is no longer an option to 'add to favourites' when wanting to save your favourite YouTube videos.The only was to now do this is by manually adding them, which sucks because you first have to copy and paste the address-bar into the Options box.I have uninstalled and reinstalled it three times now and it's still the same. Also, where are my 'backups' stored? I'm bored of having to try remember all my saved videos everytime I need to reinstall it.I once gave 5 stars, sadly now, you barely get a 2.Sort it please. Thanks x

UPDATE:
Thanks for the swift response and informing me that the old version was broken and supplying a link to the new version.
It works a treat again. Back to 5 stars. Awesome! *****

This review is for a previous version of the add-on (1.5). 

The latest version 1.7 is still waiting for review but you can install it from here: https://addons.mozilla.org/addon/youtube-enhancer-plus/versions
Version 1.5 is broken because of recent YouTube changes, This new version fixes those changes and bring a lot of new functionalities.

Regarding your backups, open a new tab and type ‟about:config” in the address bar. If you see a warning, click on ‟I'll be carefull, I promise!”. Type ‟extensions.youtubeenhancerdotcom.playlist” or ‟extensions.youtubeenhancerdotcom.videos” in the search field located above the preferences list, right click on the one you want and select an option.

Hope you will enjoy it and will change your rating.