Download failed. Please check your connection. -- Firefox contains add ons in one window but not the other.
I run Firefox on multiple profiles so I can login to various accounts at the same time [note: I'm aware of sessionbox but I prefer using this method].
Today my adblocker add-on and new-xkit add-on uninstalled themselves and the browser suggested I install them from the official add-on site. When I went to do so, I found I couldn't download any add-ons. I kept getting the message 'Download failed, Please check your connection.'
My connection is absolutely fine, I've done everything I could think of. I reset my modem and router, I restarted my computer and I relaunched Firefox. On my main session, everything is AOK-- but when I go to open another session [or even CREATE a new one] I'm met with the same error time and again-- no matter WHAT add-on I'm attempting to install.
My next step is to try a VPN-- if that fails I'm at a loss on what to do. Without the add-ons I frequently use I'll likely abandon Firefox and start using another browser.
Additional System Details
- Shockwave Flash 17.0 r0
- User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:66.0) Gecko/20100101 Firefox/66.0
Sorry, the Add-ons team is working on a fix for this. It looks like a certificate used to sign many popular extensions expired. The verification process performed during download checks that certificate.
I don't know how soon re-signed versions of those extensions will become available, or whether another workaround will be discovered. We are all hoping to learn more soon.
The Forum shows your Adobe Flash Plug-in is out of date. (Version 17.x.x.xxx)
You're running an older version, which can cause problems and be a Security Risk.
If you don't use it and do not keep it updated, you can Disable or Uninstall it.
Mar 12th, 2019...
Latest Adobe Flash Version (220.127.116.11).
In the FireFox Browser, go to Add-ons > Plug-ins and click on the Shockwave Flash Options to check the Flash version.
Flash seems not to Automatically Update, so you need to keep a regular eye on these for Updates. (Flash Support will end in FireFox at some point down the road.)
You can update Flash from your Anti-Virus Program's 'Software Updater' area (Avast can do this) or on Adobe's Website:
Upon having an older version, go to step 2 on Adobe's site (the link referenced above) to download the latest version:
Note : UnCheck the boxes for the additional sponsored software that is offered on the download page if you do not want it also installed.
There was a Bug-A-Boo with a Certificate Expiration Date dealing with the Add-ons. There's a new FF Version with the main Fix, 66.0.4.
Mozilla Blog Post Update:
A Firefox release has been pushed — version 66.0.4 on Desktop and Android, and version 60.6.2 for ESR. This release repairs the certificate chain to re-enable web extensions, themes, search engines, and language packs that had been disabled (Bug 1549061).
There are remaining issues that we are actively working to resolve, but we wanted to get this fix out before Monday to lessen the impact of disabled add-ons before the start of the week. More information about the remaining issues can be found by clicking on the links to the release notes above.
(May 5, 16:25 EDT)