Yes! Same issue here. Started Firefox and it said that my only addon (adblock) failed to work properly. Attempted to restart Firefox. Same thing. Attempted to reinstall addon and it said “Download failed. Please check your connection.”
My internet connection is fine. So I retried other adblock addons and the same error message appeared. Something wrong on Firefox’s end I believe?
Yeah, they fricking disable the AVAST Online Security Add-On … how fricking smart is that? Stupid devs! FIX THIS CRAP ASAP!
This is the perfect way to kill of the browser, since many that gets these problem WILL choose a new browser, without these problems!
I came here to say everything in your post. In the middle of doing something and suddenly nothing on firefox works and will not let me add on the addons I had. Please mozilla fix this, I can’t go back to Chrome it kills my laptop and Safari sucks. I need a working Firefox!
Had the same thing just happen to me. (Including the impulse to just rip and tear at my hair! 
)
All my installed themes just up and disappeared. Not to mention my AdBlockPlus! (I kinda forgot how annoying ads could be whenever they pop up. Which they do. A LOT!)
Firefox and you nice people at Mozilla, please help!!!
why would mozilla think this is a good idea? why cant an algorithm be implemented that would check for add-on security instead of sifting through each and every add-on themselves. seems a bit counterintuitive and it also seems like many people are annoyed
same here, no adblock or even browser theme. if this is not bug, but new fox politics - bb and hello chrome.
btw i use fox for a ~13 years, and now this.
I am also having this problem. I’ve been thinking about switching to firefox due to problems in the browser I’ve been using for over a decade; this is not the way to encourage me.
to summarize:
all - or almost all - extensions have stopped working
and
all - or almost all - extensions can not be downloaded
Yeah, not cool. My only - and apparently dangerous - add-ons (ublock, lastpass, and push to kindle) are gone, and as others have said, I can’t reinstall them. I’m streaming music right now so I know there’s no internet issue. Please fix this.
YEAH WHAT THE HECK MAN?! Please fix this.
I am having the same trouble as everyone else. I open up my Firefox browser and all of sudden my add-ons are gone. When I attempt to re-download my add-ons it says I have no internet connection? Except that I am streaming and able to post here?
Its frustrating because I have been making the gradual switch from the Google giant and Firefox was a great alternative. Firefox and Mozilla let me down today.
Very strange, it rebooted for me in the middle of what I was typing. No warning or nothing. Lost all my addons except 1 (WebRTC Leak Shield).
I’m having the same problem. what gives!?
I also have experienced this issue across my work and personal machines with different versions. As of now, only my 64 bit firefox has its extensions. All of the 32 bit installs are extension-less now.
It’s as if “someone” snapped their fingers and wiped out all of the extensions.
I have a 64bit Firefox and the only extension that’s left with mine is Rikaichan (=an online mouse-over for Japanese script).
Not to mention the themes I accumulated over the years! Just… Blown to smithereens…
(I don’t think someone’s got a time-machine stashed somewhere so we could go back and stop that ‘someone’ from snapping their fingers? ;-))
Hello folks. Can only speculate as to the cause of the problem but have a workaround for you until this is fixed. Not perfect but better than nothing.
Your addon will be enabled but will only work until you close firefox again. Repeat steps 1, 2 & 4 as required for other extensions you need.
Once this is fixed properly, please remember to disable addon debugging from step 3.
Another quick work-around is to manually change your computer’s date to yesterday. This will allow you to re-download your add-ons.
I have this issue as well.
It says “Download failed. Please check your connection.” but that is a lie. Downloading the addon file manually via another computer on a different internet connection, then trying to install the addon on this computer, produces the real error that the addon is corrupt.
This happens with every addon, regardless of what it is, or the internet connection I use.
It is a server-side problem.
I am switching browser to Chrome until this is fixed.
none of my adons are working your update fubred the firefox enjoyment please fix it my firefox updated today to latest version but as soon as I opened it and everything my addons were declared out of date by firefox. I re-installing and everything, but the site sometimes says, “download failed. check your connection” even when I have a very good internet conection full bars and everything and the extension downloads, it says, “addon could not be installed, it seems to be corrupted.” I tried reinstalling firefox and I still get the corrupt message. what did you do
I’m a long time ff user, too, and I’m hoping this is a temporary problem. Even the extensions that are listed on their approved list aren’t working.
Hi, guys
Please manually set your time to 5/2/2019 or before. then download add-ons again. this will temp solve the problem. mozilla is crazy. how could they remote disable my add-on? DO NOT CHANGE your time back, otherwise mozilla will disable your add-ons again.