Firefox Community Forum

Hello, I can't log in to Facebook, only through Firefox, and that's the problem. Edge and Chrome work fine. I've already deleted cookies and temporary files, and still nothing. This problem has been occurring for a while.

I just installed Firefox on my PC haven't had it on this computer since reinstalling windows - I imported my bookmarks and passwords from Edge, thinking it would be a seamless transition, since I used Firefox in the past without much trouble.

Two weeks on, about 95% of every page I open gives an error similar to the one below, and I have to shift+refresh several times to get it to reload before it goes away, (some sites still don't open).

I wonder how common this issue is, and how people fixed it?

Be careful. Something doesn't look right.

Firefox spotted a potentially serious security issue with connect.mozilla.org. Someone pretending to be the site could try to steal things like credit card info, passwords, or emails.

Go back (Recommended)

Hide advanced

Advanced What makes the site look dangerous? The site is set up to allow only secure connections, but there's a problem with the site's certificate. It's possible that a bad actor is trying to impersonate the site. Sites use certificates issued by a certificate authority to prove they're really who they say they are. Firefox doesn't trust this site because its certificate isn't valid for connect.mozilla.org. The certificate is only valid for: *. eero.com. What can you do about it? Probably nothing, since it's likely there's a problem with the site itself. Sites use certificates issued by a certificate authority to prove they're really who they say they are. But if you're on a corporate network, your support team may have more info. If you're using antivirus software, try searching for potential conflicts or known issues. View the site's certificate Learn more about secure connection failures Error Code: SSL_ERROR_BAD_CERT_DOMAIN Jun 5, 2026 10:58:34 AM GMT+10

Proceed to connect.mozilla.org (Risky)

After Windows 11 Home's Microsoft password manager supports passkey, I have troubles with passkeys in Microsoft password manager, not Windows Hello.

1. Firefox failed to login into sites with passkeys in Microsoft password manager tied with sites.
2. After Firefox added a passkey into Microsoft password manager (at that time, no error occurs and display succeed messages), Firefox an Microsoft Edge (Chromium based) fails to login by the passkey. And this trouble continues after Edge replaces the passkey tied with the site.

So, I can't use passkeys in Microsoft password manager.

Have you heard something like this troubles?

OS: Windows 11 Home 25H2 (Japanese locale) Firefox 151.0.3 (x86_64 with Japanese locale. On second trouble, I used the latest version at the old time) Edge: 149.0.4022.52 (Official build with Japanese locale)

Adding this post for SEO indexing purposes, as I cannot reply to the original archived one: https://support.mozilla.org/en-US/questions/1321170

The original post is one of the top search engine results, and provides a bandaid solution, without addressing the proper root cause, so I want to help whoever stumbles over this.

Original problem:

Dale 1/9/21, 8:26 AM

Firefox Developer Edition 85.0b4, macOS 10.15

If I Google for a PDF and click a link, I get the Firefox download dialog. If I select "Open with Firefox [Developer Edition]", the following things happen:

   The PDF is downloaded to ~/Downloads
   The PDF is opened in a new tab, with that new tab's location bar holding a file:///... URL to the downloaded PDF 

What I would instead like to happen is:

   The PDF is downloaded to some temporary directory where I won't have to worry about deleting it manually
   In whatever tab the PDF is displayed in, the location bar contains the URL where the PDF was (temporarily!) downloaded from 

How can I achieve this?

Not having the URL where a PDF was opened from is very annoying when, for example, I open a bunch of PDF search results to read and review, and I later want to share links to some of those PDFs. Best I can do to find their URLs to give to others is then to try and remember which tab corresponds to which search result, or do mine the downloads tab.

Contrast this with Chrome: I click a Google result for a PDF and the PDF just opens in the current tab with the URL to the PDF in the location bar. No dialogs, no PDF files hanging around in my home directory, and I can just copy the URL to the PDF the same way I'd copy the URL to any web page.

Thank you!

Proposed solution by original poster:

Dale Question owner 1/9/21, 9:27 AM Chosen Solution

Sigh. It appears the problem was one or both of the following preferences:

   pdfjs.enabledCache.state: false
   pdfjs.migrationVersion: 2 

I deleted both, and now clicking on a PDF just opens in the sane, normal way in Firefox that I desire.

Naturally I have no idea how those got set.

I installed Firefox Developer Edition and I am having the following issues, whenever I go to Indeed and I go to a job posting the browser opens up additional tabs without my permission or me doing so. Also the browser does the same in Canvas when I go to my course the browser automatically opens up new tabs without my permission and also me doing so. The Firefox Developer Edition browser update is Firefox Developer Edition is up to date 152.0b7 (64 bit). The following extensions are installed AdBlocker Ultimate, FoxyProxy Basic, Ghostery AdBlocker For Privacy, Malwarebytes Browser Guard, Privacy Badger, and UBlock Origin. This behavior got super annoying and I don't know how to fix it. Any help on how to fix this would be appreciated. My operating system is Windows 11.

So I clicked into a video, and it did not play. Further troubleshooting showed it was a video hosted by vimeo, and youtube videos still worked. I tried on multiple vimeo hosted videos, on multiple unconnected websites (dropout, patreon, and directly on the vimeo website).

I tried the following fixes:

• I opened it in a private window and nothing played.
• I booted into safe mode, still nothing.
• I turned off all of my add-ons, nope.
• I cleared my cache and restarted, nothing.
• I cleared my browsing data and restarted, also nothing.
• I checked for updates: up to date.
• I created a test profile, and it works there.
• I opened Chrome and it worked there too.

The test profile/chrome thing suggests it's an add-on or something but the fact that I turned them all off and this still happened has me baffled.

Update: I fixed it. Was user error.

duplicate of /questions/1585147 thread

I am having trouble logging in to my Firefox account. When I try to sign in, it does not work. I have already tried resetting my password, but the issue remains.

Hello,

I'm using version 151.0.1 (64-bit) in France. I don't see the VPN configuration prompt in the top-right corner of my Firefox toolbar, nor do I see the VPN icon in the toolbar… What should I do, please?

Thank you in advance for your help