What site(s)??? Provide steps to replicate the issue.

Websites such as: Nexus Mods (this is usually the site with the most problems). Sky Mods. pxhere (stock image site) metal-archives

These are just a few I have visited regularly, it seems every Cloudflare run site is having problems loading. I have Flagfox which informs me of the web server and location. It would be impossible to list every single Cloudflare site I have visted because almost 70% of the sites are run by them.

How to replicate the issue? I open a site I want to visit and then it either spits out a Firefox error or gives up trying. Using presenting a blank webpage. The error usually recieved is, "PR_END_OF_FILE_ERROR".

Is this the site? see screenshots https://www.nexusmods.com/ https://smods.ru/

What security software are you running? Have you tried in Firefox in Safe Mode? https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#search

At the moment I'm using Kaspersky. I tried others but Kaspersky offers the best protection.

I haven't tried safe mode, I will give that a try.

You mean the sites are hosted by Cloudflare? What does run by Cloudflare mean?

That's what I meant, sites hosted by Cloudflare. Sorry, my explanation wasn't clear.

Other sites hosted by OVH SAS, Amazon and others seem to be fine. Only Cloudflare hosted sites are having problems.

I'm a Kaspersky fan also in Windows. Can you disable it, reboot and try again.

Okay, I'll try that and get back to you on the results.

So, I tried disabling Kaspersky and restarting. It worked...for about a minute or so and then the sites once again stopped working. The usual mix of "PR_END_OF_FILE_ERROR" and blank webpages.

I'm starting to think that is maybe something to do with my ISP or my equipment. But why do other sites hosted by others have no problems...and only Cloudflare is having difficulties?

For a comprehensive explanation of that error and suggested remedies (remove blank space in link). It's unique to Firefox. https://appuals. com/pr-end-of-file-error/

For a comprehensive explanation of that error and suggested remedies (remove blank space in link). It's unique to Firefox. https://appuals. com/pr-end-of-file-error/

I have already read this page, not to mention read other sites and pages about Firefox errors. If they had solved my problem, I wouldn't be posting on a forum and asking other people for a solution.

Hey ichigatsu san,

Just curious, but who are you using for DNS?

Hi Jonzn-sama.

I'm not using any DNS or any proxy either.

If you open a command prompt and type in ipconfig /all post what you get. https://lazyadmin.nl/it/ipconfig-command/ Also look at you proxy settings. see screenshot Once in the settings you can just type proxy up top to find it.

What is your home setup? Are you going through a router and then modem or just to a modem? For me, my laptops connect to a Linksys router and then to a Arris modem.

If you open a command prompt and type in ipconfig /all post what you get. https://lazyadmin.nl/it/ipconfig-command/ Also look at you proxy settings. see screenshot Once in the settings you can just type proxy up top to find it. What is your home setup? Are you going through a router and then modem or just to a modem? For me, my laptops connect to a Linksys router and then to a Arris modem.

I don't use a proxy. I'm connected via a Netgear router which is connected to a modem with speeds of 1Gbps and behind a Kaspersky firewall.

Actually, I think I may have found the cause. Adguard. It seems that Adguard wasn't effectively blocking all adverts and as such the bandwidth and latency was being flooded. After uninstalling this and installing Adblock Plus, which was my default blocker on Opera before switching to Firefox, all adverts are being blocked effectively and the problems seem to have disappeared. Every Cloudflare hosted site is opening and running without problems.

Thanks for all your suggestions. They were really helpful to getting to the root cause of the problem.