Firefox Community Forum

Hello,

I have had an issue for a few months now where certain websites fail to load. This is most easily reproduced on https://addons.mozilla.org, where I am shown the error "An unexpected error occurred" on most pages, preventing me from installing addons.

This issue does not occur in a Private Window, in Troubleshooting mode or in Chrome or Brave, but persists in fresh installs of Firefox. In troubleshooting this issue, I have removed all program files, registry data, and app data pertaining to Mozilla / Firefox. In fresh installs, I can sometimes install an add-on or two before this error starts occuring. I have not imported any previous data.

I was previously installing from Chocolatey, but in my last clean install, I downloaded from the official website.

I am on Windows 10 and Firefox 157. I use Proton VPN (Paid) and have tried changing servers several times to no avail. Again, this only happens in Firefox in a standard window, Private Mode and Troubleshooting Mode are fine.

Screenshot 1 shows the issue from my most recent reinstall. I was able to install 1 add-on (SponsorBlock) before it started showing up. Removing the add-on doesn't fix the issue. Trying to access addons.mozilla.org via a search engine results in the tab icon loading for a second and no change happening on screen (Screenshot 2).

I experience similar issues on other websites, like trying to log into Bandcamp.com (logging in gives the error "There was a network error. Please try again."), but most sites work.

Loading https://addons.mozilla.org/en-US/firefox/ gives the following results in the Network Console:

Uncaught (in promise) TypeError: can't access property "pressed", target is null

   onChangePermissions chrome://mozapps/content/extensions/components/addon-card.mjs:893

addon-card.mjs:893:7 Reporting Header: invalid JSON value received. collect Reporting Header: invalid JSON value received. collect Reporting Header: invalid JSON value received. collect Reporting Header: invalid JSON value received. collect Reporting Header: invalid JSON value received. collect Reporting Header: invalid JSON value received. collect

I regularly consult this web-site https://eservices.dls.moi.gov.cy/#/national/geoportalmapviewer It is a government land registry website. A lot of it still works (the least useful parts) I need to use the Interactive Maps but now instead of a nice map of Cyprus I got a message saying there was a problem with the web-site. I accordingly switched off enhanced in the shield and now get "The specified URL cannot be found. " Aaaargh! I've raised a query with them but I'd just as soon learn from anyone who could help. Thanks

Hi,

I’m having an issue while using a web proxy service in Firefox. I’m trying to access Croxyproxy Croxyproxy, but I’m not sure whether the problem is related to Firefox settings, cookies, JavaScript, or Tracking Protection.

Has anyone experienced similar issues when using Croxyproxy with Firefox? Are there any Firefox settings I should check to make sure the website works correctly?

Thanks for your help.

Over the past few weeks some web sites have not been working properly on my PC. The site will open but I am unable to open individual pages within the site. This has occurred only on a few web sites, such as the UK met office, while other sites, such as XC weather, are unaffected. I have tried the web sites in another profile, using private browsing and refreshing Firefox but there is no change. However, if I open the Mozilla VPN and then try the problem goes away. The web sites also work correctly when using the Edge browser and when using Firefox on my laptop and mobile.

I routinely check out several local news outlets' websites and for the last 2-3 weeks, since a Firefox update (using FF 156.0.1 (64-bit) on Win11, v25H2, Build 26200.9550) I keep getting a Norton popup box saying "we prevented your connection to <x> because it is a malicious website", where 'X' is either littlestastronaut.com, or something like planted.com (screenshots of Norton popup windows doesn't work). This doesn't happen with any of the other couple dozen websites I visit, just 2 out of the maybe 5 or 6 different news websites I look at. Odd thing is I look up either of these two 'dangerous' websites and they either don't exist or they are some school related website. That popup comes after I have to select either "continue without ads" or go to the FF address bar and disable the ad-blocking for that site, so I'm thinking that there's maybe something in FF that is causing this? It happens on both of these sites whether I check "continue without ads" or disable the FF ad-blocker which doesn't make sense that that 'malicious site' is contained within an ad on the news site because on one I don't disable ads so it shouldn't even come through but still Norton catches it??? Yes, A-I will one day rule the world....ya-right.

every time I do a search this comes up: with captcha;About this page Our systems have detected unusual traffic from your computer network. This page checks to see if it's really you sending the requests, and not a robot. Why did this happen? I have already uninstalled and did a refresh but nothing works

Recently any web site that runs Java scripts will not load in my browser unless I have VPN turned on. The web sites used to load with no problem. I don't know what's going on. Can anyone help me with this issue. ML

I get incessant popups that a virus has been detected from McAfee and to press the Delete Viruses button. I only hit the top right X to make it go away and then at least 10 more immediately pop up. How can these be removed. They even show up over other browsers as a right side popup.

I'm at the point of removing Firefox. How can these be removed from Firefox?

I followed directions for "Secure Connection Failed" and I still get the screen when I reopen the email account. I went to Avast, Settings, Protection, Core Shield, Configure shield settings-Web Guard and unticked Enable Https Scanning. I hoped by following the directions found on your website the problem would be resolved. Now What do I do to get into my email account?

Firefox with MAC OS 11.7.11 no longer works with SURFSHARK, TRANSMISSION OR FOLX I have reinstalled those applications I can start with my VPN (SURFSHARK) but as soon as I access a bit torrent, Firefox no longer functions.

Your VPN has not been working in Russia for 5 days now. Just to write this, I have to wait about a minute on every page. Why does your browser work so slowly in the support section? The same site opens much faster in Chrome.

When I try to go to Google's website, I get this message:

Secure Connection Failed

The page you are trying to view cannot be shown because the authenticity of the received data could not be verified. What can you do about it?

The issue is most likely with the website, and there is nothing you can do to resolve it. You can notify the website’s administrator about the problem.

Error Code: PR_CONNECT_RESET_ERROR

The same thing happens with YouTube TV. My Bitdefender also flagged it as a suspicious page.

I am using Firefox Beta 156, Version 4 on Windows 11 Professional, 25H2. I have an odd error, "Look up over IPV6 failed lookup." It occurs on two different VPN's, Proton Free, and Windscribe Professional. Any assistance, or insight would be highly appreciated. Thank you kindly.

I’ve been having some connection issues while using Mozilla VPN with Firefox. Some websites either load very slowly or occasionally fail to open until I disconnect the VPN.

I’m trying to understand whether this is more likely to be related to Firefox, the VPN connection itself, or the server being used.

I’ve also been looking at other VPN options such as CometVPN and was wondering whether changing providers could realistically make a difference in this kind of situation, or whether I should first be checking Firefox/network settings.

Are there any specific DNS, proxy or Firefox settings that are worth checking when troubleshooting this type of VPN connection problem?