What a hilariously bad launch of a feature. Would love to at least be invited to consent to having my experience unceremoniously screwed.
You can manually download, open debug add-on, select load tempory add-ons and select the add-on but you have to do that each session. This new updates seems to have broken a lot of add-ons. I get Download failed. Please check your connection for the add-on adblock plus and honey .
This isn’t the launch of a feature, a certificate expired.
I am having the same problem too, but ONLY on my desktop PC and NOT on my laptop. What the heck is going on!? When I went to check on my desktop PC I got this message Download failed. Please check your connection. There’s NOTHING wrong with my connection!! Please FIX this so I can re-install the theme and other add-ons that I want to add. This is ridiculous with Mozilla constantly making changes and not making add-ons compatible with the ahem…latest Mozilla upgrades. Such as YouTube Classic and now I can’t add it to my desktop PC. Mozilla is ALWAYS making upgrades to its browser but FAILS to make add-ons compatible with its upgrades. That is UNACCEPTABLE, because not doing so is like you’re in the stone ages. PLEASE FIX THIS GLITCH, if that’s what it’s called.
An article that is a good explanation and summary of this whole fiasco: https://techcrunch.com/2019/05/03/a-glitch-is-breaking-all-firefox-extensions/
We’ll be providing updates on this thread: [FIXED] Certificate issue causing add-ons to be disabled or fail to install
My icons for add on’s disappeared too. Looked for “video downloader” and it is no longer there. It would appear Firefox reached into my computer and did a change. I have been with you guys since Netscape, but it looks like it is time to move on. Nice how you can not reach a person to talk to at you business. I guess it is time to move on to a different web browser.
Firefox did not reach “into” your computer, nor did it update for this to happen. Please check out https://support.mozilla.org/en-US/kb/add-ons-disabled-or-fail-to-install-firefox for how to fix this problem. The TL;DR is that you should ensure Firefox is on the latest version.
Hi
Thanks for the reply. I checked the version of Firefox and it says I am using version 67.0. I assume Firefox reached in and updated my old version to the current version of 67.0 and deleted my "video downloader and "adware" programs. I did get programs that are similar but not the same. I assume those programs are no longer supported. I did reach someone in you support area and they took over my computer, and they informed me that my computer had 28 net connections and that I needed to pay 199.00 to fix the problem via VPN. That my current VPN was only good for antivirus. After paying someone to inspect my computer, as I did not have the 199.00 to fix. The person tracked down all the PID numbers and found out thy were all program related numbers and needed and the 199.00 fix was presumably a wifi router which I have but have disconnected to be safe. The tech I had inspect my computer suspected as much as I was still showing all these connections even after I disconnected my WiFi router. It would appear that the tech I talked to was just trying to sell me something. The article you referred me to was for a May 3rd update version. I assume my problem occurred with the update push for 67.0 version and the extensions I had are no longer supported. The tech I talked to was just uncool it would appear. He never answered my original question on where my add on programs went. He just cost me money as I paid for a tech to inspect my computer. I am old, disabled, and poor so this was so uncool.
Thanks for the reply, but the article you referred me to was of no help as it referenced an older Firefox version, so was of no help.
That doesn’t sound like someone from official Firefox support. Especially because they wanted to charge you a lot of money.
It is possible that the extension you were using got blocked and is thus no longer available. Finidng a replacement may not be simple, however searching for “video downloader” yields a lot of extensions on addons.mozilla.org.
Hi cloudi, Firefox 67 introduces a new default-release profile and incomplete migration is creating problems for some users. They need to manually switch back to their older profile using the about:profiles page. Please check whether you can do that, using the “Set as default profile” button and definitely do not use the Remove button there.
For more assistance with Firefox 67 issues, please try Mozilla Support: https://support.mozilla.org/
Regrettably, it has a separate sign-on system, so yet another login!
Hi
Thanks for the response. I give up as I do not understand your response. The link you give is for the support page I have already seen, and I can not find any articles in search that addresses my problem, nor can I find the add on so I give up . I will just assume the "Video Down-loader" and " Adware" extensions are not supported any more. You do not need to respond unless you wish you provide link to a article that explains how to get the extensions back or tells me that the old add on are no longer supported otherwise referring me to the generic support page is not helping me. (been there done that) I guess I am just to stupid. Thanks for trying to help.
Hi
Thanks for the reply. I got the phone number by doing a search for a support phone number. Of course looking for Firefox, makes looking for a phone number with in the Firefox program next to impossible, so I give up. The link looked official but of course I am sure it could be spoofed and I guess google can not be trusted anymore.
Hi cloudi, my suggestion is to ask your question on Mozilla Support rather than using this forum.
https://support.mozilla.org/questions/new
Since you need custom assistance, scroll down past article suggestions provided during the new question submission process to continue with the form. Toward the end you’ll be asked to register on the site.
Mozilla does not provide phone support, so you are correct that an official phone support number is impossible to find.
I used to have this problem with Firefox…it was fixed…but now I have the same one with Comodo Ice Dragon! Is there goin’ to be a fix for it as well?
That’s something you’d have to ask the people that maintain Comodo Ice Dragon, which is probably Comodo.
Since it uses only mozilla addons they throw the ball on this court…mozilla bug they said…
Well, Mozilla patched their own product, so Comodo should follow the patches that Mozilla applied (they are in the public source code for the Firefox releases that fixed it…)
I’ll give it a try…thanks for your time 
Try the manual import method for now: https://www.jeffersonscher.com/ffu/armagadd-on_2_0.html (under “Other Versions of Firefox”)