hello Cural42, normally such issues are caused by a firewall/security software which doesn't recognize & therefore blocks new firefox versions: Fix problems connecting to websites after updating Firefox

Already tried that before. I don't even have any software firewall currently active, and the hardware firewall in my router does not block individual applications. It blocks ports instead, by IP address. My Avast AV software does not have anything that blocks applications either, since there is no firewall aspect to it, just the anti-virus software. Likewise, my Spybot S&D has no blocking capability either.

I followed all the steps in the article titled "Firefox can't load websites but other browsers can" when I tried installing v24 and v25 last night, which included the steps from the article you posted above with regards to firewalls, as well as changing proxy settings, disabling IPv6 and DNS Prefetching, and resetting Firefox defaults from the troubleshooting page, which blew out all my settings, and still nothing.

I had tried all the steps I could find on these pages, which is why I thought I would post my issue, since I had run out of ideas. I even took a look at the info about the issue some people are getting where it works for them only if they are moving their mouse, but even moving my mouse didn't get any results for me.

What did you get when pages didn't load -- server not found? Stalled out and left the page blank or previous page on screen?

I think it was "Page not found" if I am remembering correctly. I would need to reinstall one of the affected versions to be certain, which probably won't be until the weekend.

Might be a dump question, but did you restart after you installed? And then run updates of your security software?

Go look at your plugins, also - maybe you don't have the right ones for the new release. I am an IE guy just now using Firefox, but I was in mainframe support for 40 years, and some pc stuff. Good Luck!

Yes, I did a restart, but it didn't help. I don't have any applicable security software that I can update. My hardware firewall is from the router, which does not have an option to block applications, and is the latest firmware version anyways. There was no software firewall, and my only other security software are my Avast anti-virus and my Spybot S&D to keep spyware off the system. Neither of them allow me to block applications, since there is no firewall aspect to them.

I have also confirmed that this issue is occurring for me from at least as early as v12 of Firefox, since for some reason when I went to open Firefox tonight, my system auto-updated me to that version, even though I have automatic updates disabled, and have never even downloaded that version! (I downloaded v24 and v25 when first experiencing this issue, and just last night I downloaded, but have not yet tried, v7, v11, and v18, so that I could start narrowing down which version the issue starts at. Guess I can get rid of the v18 one now.)

It's hard to remember years later, but Firefox 12 might have been a "forced" update for Firefox 3.6 users on platforms that supported Firefox 12.

Perhaps you can use the "Portable" build of Firefox 3.6.28 — warning: 3.6 is NOT SECURE! — until you are able to debug Firefox 25. More information is available on the PortableApps site (click "Other Versions" below the big download button to get a link to 3.6.28).

Actually, it might be a good test to see whether Portable Firefox 25 will run. If that will run, the issue with your regular install could be a severe problem in your profile that wasn't cleared by a Reset, or a severe problem in the program folder that wasn't clear by upgrading, or a registry problem.

I meant to say, check the FF Add-ons under Tools. If you can't see Tools, hit your Alt keyboard key once to bring up the bar. I'm wondering if you have an Add-on that is not compatible. Just a guess. Some say to come up in safe mode by holding down the shift key while launching FF to disable add-ons, etc., to see what happens. I don't know if one of those security packages might have not supported FF, or did it differently, and now they need to be updated or even reinstalled.

Well, I have just successfully upgraded to Firefox 7.0.1. It is loading web pages successfully. Have not yet tried the most recent suggestions, though I'm pretty sure I had all add-ons disabled as part of my original troubleshooting.

So it appears whatever is causing my problem, it lies somewhere between v8 and v12.

I think I'm going to try v9 next and see what happens.

New update:

Firefox v11.0 installed and working. Whatever the issue is, it starts with v12. Must be something that was changed in v12 that is not being compatible with my system for whatever reason.

The top advertised changes in Firefox 12 don't sound relevant, but there are hundreds of changes in each release.

• https://www.mozilla.org/en-US/firefox/12.0/releasenotes/

What's your Windows XP Service Pack level?

Using SP3. I've got my OS updated to the max version for both the SP and the .NET framework.

But no need to further investigate this. For some reason, updating from v11 to v25 worked, and I can browse on v25 now!

So everything's fixed. Thanks much to everyone who posted suggestions or tips. Even though they didn't seem to help in my situation, it was great to have a community available that could offer that advice!

Perhaps the issue is just with upgrading from a really old version to a really new version, or perhaps one of my other upgrades created a fix of its own that resolved the issue. My path to success was v3 > v7 > v9 > v11 > v25.

Was a bit cumbersome, but it worked, and in the end, that's all that matters!  :)