I-Firefox Community Forum

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.

WHY DO I KEEP GETTING THIS ERROR???

"The bookmarks and history system will not be functional because one of Firefox's files is in use by another application. Some security software can cause this problem."

I never got this before but now i get this every week. restarting my computer does not fix the problem. this sucks! the article to fix this are way too complicated. how do I fix this? I use Ccleaner and reboot, but that does nit fix the issue either. HELP!

I'm using Windows 10 on a PC. Norton Security app is preventing web browsing by Firefox. The message I get is: "We prevented your connection to ful.hartonly.com because it is a dangerous webpage. Threat category: URL:Blacklist" I can still web browse using Google Chrome without any problem. What is ful.hartonly.com and how do I clear it?

When I try loading certain sites while using Proton VPN i get the following error message: Server Not Found. If I disable Proton VPN and enable the VPN on Firefox the site come right up. Can someone please tell me why this happens and how I can make these load using Proton VPN?

April 21, 2026 Tuesday

Thank you for your being here as a volunteer to answer this type of question:

IS eset.com security software compatible with Firefox Mozilla ?

Thank you,

Oliver Jeffrey

east@west.net 24/7 LA California

I was in contact with Bitdefender Support and they suggested the following:

If Facebook still won't open, open Bitdefender and:
  - Go to Protection > Online Threat Prevention > Settings.
  - Turn OFF "Encrypted Web Scan" temporarily.
  - Now reload Facebook in Firefox.

Afterwards, I also had to click on "Messenger" to get all my contacts.

This is temporary since before FF 150, Bitdefender ran with "Encrypted Web Scan", and I had no problem in loading Facebook. So something that changed in FF 150 conflicts with Bitdefender's "Encrypted Web Scan".

Hi. I run Pop_os 24.04 linux and have run the latest updated firefox for linux and the latest expressvpn for firefox and am not able to get firefox to connect with the vpn "on". It did work a week or so back but not now. With the vpn on, firefox takes at least 15 seconds to load. I've run the troubleshoot mode and it didn't help. Are there settings on firefox that could be the issue or is it a vpn problem? Thanks

Certain websites can be reached and displayed, however when using their page search, it says access denied on this server. I've tried using another browser but the same message comes up. However, on my phone, and tablets, I have no problem.

when visiting websites using my vpn firefox blocks my entry. I have to disconnect my vpn to allow entry to sites. ive tries numerous fixes and nothing works its frustrating.

My anitvirus software is blocking a website that I use. Its legitimate. How can I unblock it?

An error occurred during a connection to radoneyepro.com. PR_CONNECT_RESET_ERROR

Error code: PR_CONNECT_RESET_ERROR

   The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.