[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??

[Jiaz]

Just update your Firefox and not have to deal with anything of that at all.
With fixed FF version you can just enable the extension again.

Also you don't have to *Load Temporary Add-On* and can simply install it as normal extension.

[daffdaemon]

I uninstalled the updated firefox back at version 56 when the 'new and improved' firefox was using 3/4 of my RAM and broke all of my add-ons. I 'froze' firefox at 51 which is the last, IMHO, decent version.

When I'm finally forced to start using f**cking Windows 10, I'll probably have to get a new computer. At which point I'll be dropping firefox alltogether.

Until then, hopefully the workaround I found might help other diehards resist the inexorable evolution of computer software towards dysfunctionality.

[Jiaz]

Maybe you should give newer FF a try? I'm using FF daily work with average 20-40 open tabs and can't see any *huge* memory usage. My development environment has larger memory usage than FF and chrome combined

[daffdaemon]

Jiaz, Maybe I will. I'm curious, how much memory do you have? Are you using Windows 10?

[Jiaz]

I'm working on Ubuntu Mate 18.04 and Window8/10. At home on Windows 10.
Primarily Firefox on work. At home Chrome