Firefox Community Forum

Please help, a very tricky problem: Work Scenario: I need to use the company-provided VPN software to access the internal network. Its principle involves redirecting requests to a virtual network interface before sending them out. On Ubuntu 24.04, both Firefox 140 and older versions can access both internal and external networks normally.

Issue After Upgrading Firefox: After upgrading to Firefox 141, all connections (internal and external) fail when the VPN is active.

Key Symptom Observed: In the Firefox networking debug page (about:networking#dns), the DNS suffix should display as localdomain, but after upgrading to Firefox 141, it appears empty.

why does firefox blocks incoming http conection to localhost:8080 when I try to obtain a google oauth2 token using oauth2.py ?. The Google server returns the token via http to loaclhost:8080 and the port is blocked by firefox.

Hmm. We’re having trouble finding that site.

We can’t connect to the server at data.digital.costco.com.

Within a minute of starting Firefox up, it loses internet connection and prevents the computer from connecting to anything else. Using Ethernet or Wifi doesn't work. The only thing that corrects it is restarting the computer. List of things we have tried: Troubleshooting Mode in Firefox Removing all addons Uninstalling and Reinstalling Firefox with the latest update Disabling DNS over HTTPS Clearing Firefox's DNS cache Clearing the computer's DNS cache Adding IPv6 to our standard IPv4 connection Rebooting the router Used a new Firefox profile Run a virus scan

This is on Windows 11. There are multiple other computers on the network, with W10 and W11, and none of them are having this issue. I've tried everything I can think of. After losing connection, it still pings 8.8.8.8.. Is there anything else we can try?

For two days I have been unable to access the internet using my default Mozilla Firefox browser. I have used Mozilla as my default browser for many years with no problems, but have had to use alternative browsers not only to access my emails on Outlook, as well as other nominal sites, but even to sign into my Mozilla account, I had to use Microsoft Edge browser. I have made no changes to my settings or internet security. Please advise. Thankyou

Firefox has started crashing immediately upon launch. The browser window never even opens, and all I see is the Firefox crash reporter. This problem just started today. Everything was working fine previously.

I have tried opening Firefox in troubleshoot mode, but it still crashes. I've also done two clean reinstalls, deleting all Firefox files in between. This has not helped either.

I've attached a screenshot of the detailed crash report. In case it's relevant, I'm running Windows 11 on a Microsoft Surface laptop with Snapdragon X processor. I know the Snapdragon has had some software compatibility issues, but Firefox had worked fine on it until today. I'm totally stumped, and appreciate any ideas!

This has been a problem for me for a very long time, and I'm tired of having to use Chrome every time there's an update to Firefox.

The issue I have is that I will get the notification saying there's an update. I click the button to update now, the browser opens the auto download page and I get a not secure connection warning. The only work around I've found is to use Chrome, and sometimes I can use the "Other downloads" option.

I'm not running a VPN, or any other networking software on my pc. This is for the full program, not the Windows Store app.

Secure Connection Failed

An error occurred during a connection to download.mozilla.org. The server uses key pinning (HPKP) but no trusted certificate chain could be constructed that matches the pinset. Key pinning violations cannot be overridden.

Error code: MOZILLA_PKIX_ERROR_KEY_PINNING_FAILURE

   The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
   Please contact the website owners to inform them of this problem.

the msg returned

Hmm. We’re having trouble finding that site.

We can’t connect to the server at marvelsearch.com.

If you entered the right address, you can:

   Try again later
   Check your network connection
   Check that Firefox Developer Edition has permission to access the web (you might be connected but behind a firewall)

i am using a local dnsserver and firefox is connected to it. is this the reason? if so how can i disable this? other firefox features are working beautifully.

The following is what happens when I try to logon to AT&T Yahoo mail/Currently.com "Something's gone wrong We may be having trouble with your connection. Connecting your device to Wi-Fi could help fix the issue or try again later. If you were using an app, close this page. Otherwise, start over."

I get the USPS informed delivery emails that show what mail is arriving daily. Whenever I click the "dashboard" link, I get:

Bad Request

Your browser sent a request that this server could not understand. Size of a request header field exceeds server limit. If I go to the site, and click a link, the same thing happens. This doesn't happen with Chrome where links function normally. So, I think there must be a setting somewhere preventing me from accessing the links. I tried turning off "Block pop-up windows," but that had no effect.

Thanks, Ed

I have Express VPN and use Firefox as my default browser. This morning I cancelled the autorenewal of Macafe and uninstalled it from my HP Laptop. Now I cannot access the internet if the VPN is activated - using Firefox or Edge. Thank you

Google Services are having blackout issues when being opened in Firefox. The ones I have tried and having issues are Google Maps and Google Sheet. Things I have done so far

Change DNS Added google.com and other google services in the exceptions

Attempted to do an Firefox update more than a month ago on my HP (microsoft windows) computer. Everytime I open my computer I gt the Firefox Crash Reporter Window. When I hit the Quit firefox box it submits the crash report and then I X out the box. I cannot use Firefox as a browser. The DISASTER is that I CANNOT open any files previously downloaded while using Firefox (eg PDF files). I get the crash report box. I NEED these files!

Please HELP!