Hi there,
What you're referring to is related to an issue with an expired certificate in Firefox, causing ALL add-ons to be turned off.
Firefox has now pushed a fix for this, which should be installed automatically for you in the next hours. You can find more information on it here: https://blog.mozilla.org/addons/2019/05/04/update-regarding-add-ons-in-firefox/

If this issue still exists past Sunday, please reach out to us via support@adblockplus.org!
Thanks,
Jessy
ABP Support Team

Thank you!
Firefox has also already pushed a fix for the add-ons. You should receive it within the new hours. Please let us know if the problem persists past Sunday.

Thanks!
Jessy
ABP Support Team