There is an easy fix though. If you find yourself with a new version of Firefox, but without some of your favorite add-ons, follow the steps below to stop Firefox from automatically disabling add-ons. (Note, this does not make the add-ons work with new versions, and some add-ons may turn out to be truly incompatible.)
- In the Awesome Bar (the address bar for the unindoctrinated), type about:config and press enter.
- If you've never wandered into this territory before, Firefox will warn you about the page; click'I’ll be careful, I promise' to continue.
- Right-click anywhere inside the window and select New > Boolean.
- For the preference name, enter extensions.checkCompatibility then click 'OK'.
- For the preference value, select False and then click 'OK'.
Voila! You can now use outdated add-ons in Firefox...whether or not they actually work.