[daffdaemon]

I searched threads and didn't find any other reports, surprisingly!
About 5 days ago Mozilla f**k-up caused all add-ons in Firefox to be disabled.
Also would not allow reinstalling. Supposedly fixed by update, but if you're using an older version of Firefox there IS no fix.

I started this thread to ask for help, but while I was typing I thought I'd see what I could find on my own. Here's what I found:

1. Visit about:config and set xpinstall.signatures.required to false. This disables the extension signing mechanism in Firefox, the system through which the browser verifies that the local extension is one that's been installed from the central Mozilla Add-ons repository --and for which the signing certificate had expired.

2. Visit about:addons and remove the JD extension

3. To reinstall:
Download the JD extension by "save as file" method.
Go to about:debugging.
Check the box to let Firefox start debugging the add-ons.
Click ‘Load Temporary Add-On’
Navigate to your saved file location and load the extensions manually.
(Note: the extension may stop working if you close or restart Firefox.)

Pretty clunky solution I admit.
Any better method??