Firefox Community Forum

Issue Summary: When disconnecting from a corporate Cisco AnyConnect VPN on macOS, Firefox completely loses its internet connection and throws network errors. Other browsers (Chrome, Safari, Edge) continue working perfectly on the home network. Standard troubleshooting steps—like clearing Firefox's DNS cache, changing proxy settings to "No Proxy", turning off DNS over HTTPS (DoH), and flushing system DNS—do not resolve the issue.

Root Cause: Cisco AnyConnect locks low-level socket configurations and routing rules within the active Firefox user profile (prefs.js). Even after the VPN is disconnected, Firefox remains bound to the dead corporate pipeline, a behavior that standard settings menus cannot override.

Proven Solution: The only way to clear the corrupt VPN socket locks is to completely reset the internal profile architecture:Open Firefox, type about:support into the address bar, and press Enter.Look at the top right of the page and click the "Refresh Firefox..." button. Accept the prompt. Firefox will close, securely back up your bookmarks/passwords, generate a fresh profile, and restart.Internet access will instantly return to normal. (Note: You will just need to reinstall your extensions afterward).

All the tabs, in both my profiles are constantly crashing. I cannot keep at a task for more than a few minutes without needing to restart the tab. Is this a setting problem? I've cleared the cache, and reset Firefox, to no avail. Thank you for any relevant advice and/or assistance.

I have an ASUS laptop running Windows 10 - I can no longer access outlook.com in a regular browser, but I can in a private browser. I can access outlook on my ACER laptop running Windows 7 in a regular browser and I can on my desk top computer running on Windows 7 and using the GOOGLE browser. I only seem to have a problem with outlook in a regular browser using FIREFOX on the ASUS computer. Is there something in the FIREFOX browser settings that would prevent the connection?

I tried reinstalling firefox because I wasn't getting notifications from websites. I'm not getting notifications now either. I checked my computer settings and reinstalled the software on my Mac Book Pro 2012 version 10.15.8.

I work at a small daily newspaper chain, and our website CMS is both archaic and homebrew. I only work with it sporadically, and Firefox is the best option for maintaining it.

This morning, I got the regular "Are you sure you want to delete this?" dialog box (pretty sure it's a Javascript call) with the additional check box of "Do you want (URL) to not prompt you for this any longer?" (or words to that effect).

I thought, "Great, one less click" and made that selection.

But now when I want to delete an item off the articles list, it doesn't delete at all.

I'm pretty browser-savvy, but I don't know how to re-enable that option. Any ideas?

I'm on a private home network with an internet connection. When I try to use Firefox it displays a message saying "You must log in to this network before you can access the internet".

Many websites, e.g. Amazon, won't load and an 'Open network login page' button is shown. When I click this it takes me to a Mozilla page talking about Captive Portal, but there's nothing about how to stop this happening and access those websites.

Other browsers, e.g. MS Edge, or Brave, have no problem access these websites.

How do I fix this problem?

Pretty simple. Every time I click any "news" link on my home page in Firefox it always runs into a pay wall. This is crap as these losers get a hit count to their site, get to load ads (for some people), and so on but I don't get to read the article. And who know s what kinda crap they are dumping into my cache. This needs to be fixed or the "feature" removed. This is basic privacy shit not included in a browser that tries to brag about privacy features.....

Hi, I am experiencing an issue with accessing my Amazon orders and returns when using Mozilla Firefox. While I can navigate to Amazon.com without any problems, I am now prompted to sign in to my Amazon account whenever I attempt to view my orders or returns. This pop-up indicates that it is a Firefox security issue rather than a Windows problem. This situation has only started occurring recently, and I would appreciate any assistance in resolving this matter. My Firefox version is 150.03. Thank you for your help.

why did you destroy the existing bookmark structure and replace it with something that makes no sense. I have no idea from where you obtained the url's for the stuff that's in bookmark's now. I also do not look forward to having to re-create all of the bookmarks I had in place. I won't be doing that on Mozilla! R Crider

I've never changed things from English and can't find how to change it back. There's a pop up window saying you want to have things in English. Yes I do but I don't want to do it every time I open the browser. Any help is appreciated.

what it says on the tin. went data purging with ol reliable WinDirStat and found this absolute behemoth of a file in the profiles directory for firefox. its especially weird considering the entire Firefox directory itself is only 1.5GB with this menace taking 1.3 of it. I cant imagine that bookmarks, search history, passwords, the works takes up any more than about 300mb. so im wondering if im just stuck in the early days of data or if the file really is just that girthy.

I'm reposting a question already opened here because a moderator suggested to do so. Actually I though I was posting to the international forum from the URL...

I was trying to access a local HTTPS website of an embedded device (a Siemens S7-1500 PLC) that is using a self-signed certificate, but was unable to go on (attached image #1, in Italian language) due to the the SEC_ERROR_REUSED_ISSUER_AND_SERIAL error. I've browsed a similar PLC webserver in the past, so the fact that the device exposes a similar certificate serial number is not so strange for me, considering also it's self-signed.

The problem is that I cannot follow the instructions of the Mozilla knowledgebase here because I'm not able to identify the correct certificate of the website!

In the attached image #2 you can see that the connection is detected as not encrypted, I suppose because only the form part of the HTML that is posting the data using HTTPS while the rest is using HTTP, but I'm not sure. If I click on the padlock icon (attached image #3) the info about the current certificate is not displayed.

Then I went into Tools > Options and searched for "certificates"; as you can see in the attached images #4 and #5, neither in the Servers tab nor in the Authorities tab I can find any item that is related to 192.168.10.2 (the webserver IP address) or Siemens (the embedded device manufacturer). But unfortunately the error persist! Initially there was a 192.168.10.2:443 line in the Servers tab and I removed it and restarted Firefox, but it didn't solve, so at the moment the situation is the one depicted by the attachments.

I had to use Microsoft Edge to access the website, but I would like to solve this issue and use Firefox instead. Is there anything else I can do to bypass the error? Why doesn't the error page provide a way to correctly identify the wrong certificate using its fingerprint and/or name? Or, maybe, is there a way to disable this check for local IP addresses or for items in a whitelist?

Thanks for your help.

I have just started getting Virus/Trogan messages from McAfee when brousing with Firefox. I have not installed McAfee so is this a blackmailing/SCAM by McAfee to get me to pay?. I only get these messages when using Firefox, It seems to be somthing that's got into Firefox! I don't, at the moment, have this annoyance on my Laptop.