Check with their respected Addon developer for issues with their addons.

They may need updating. Check in Add-ons and Themes (ctl+shft+a).

They have ALL been updated and still are not working. They were working a few weeks ago but as best I can tell, seem to have stopped working after the last Firefox update.

If you use Adblock Plus then you can consider uBlock Origin as a replacement to see if that works better (lower memory footprint).

• https://addons.mozilla.org/firefox/addon/ublock-origin/

As mysterious as to why those addons stopped working, they have mysteriously started working again! i hope this continues to be the case!

Sometimes a restart alone achieves that.