Firefox Community Forum

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.

My version is the most recent, 152.0.6.

After a few minutes, text searches in the address bar unpredictably stop working. This might happen right away, or it may take a while. The result is always Secure Connection Failed The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.

Here are the problems that I encounter literally every day: Randomly unable to access GMail: account selection entry screen does not respond, or drop-down account selection when logged on does not respond. Randomly unable to access URLs embedded in emails. Browser locks up unpredictably. Videos in Facebook randomly fail to render: the audio plays, but the bottom half of screen completely blanks. Randomly unable to access websites in general: "secure connection failed". Randomly refuses to search for terms entered in the address bar, with "secure connection failed". Widgets on web pages randomly fail to respond.

I'm using the VPN that comes with my AV package, and turning it off makes everything work again. However, I'm certainly not going to turn off part of my web protection (which I am paying for) in order to get Firefox to perform basic browser capabilities. TBH, all of this started when Firefox started aggressively promoting their own VPN, so it's quite tempting to put two and two together.

I would prefer not to resort to Edge or Chrome, but at this point I don't see an alternative as they do not have these problems and Firefox has basically become unusable.

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.

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?

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

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".

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?

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

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?

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!

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

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.