Some problems occur when your Internet security program was set to trust the previous version of Firefox, but no longer recognizes your updated version as trusted. Now how to fix the problem: To allow Firefox to connect to the Internet again;

• Make sure your Internet security software is up-to-date (i.e. you are running the latest version).
• Remove Firefox from your program's list of trusted or recognized programs. For detailed instructions, see

Configure firewalls so that Firefox can access the Internet. {web link}

Thank you for your prompt response. My Windows Firewall and all its settings are controlled by Norton Security. I have the latest updated Norton Security 22.11.2.7. In Norton I did Remove All Firefox exe's, then I Added All Firefox exe's back and Applied. Re-Booted. Still same. Firefox starts but hangs and can't access internet. I can access Firefox Tools, Options, etc. Strange though, Using Reload icon or right click for Reload, I can't Reload the Firefox start page. Buttons appear to be inactive? Note: When I load Firefox 52.5.3esr, it works like a champ. I've been using Firefox for many years and love it. I really need your help in being able to continue using. Thanks so much...

I would first disable or remove all Norton and get a program not so aggressive to blocking any new Browser usage. If you want FF58 I would first remove all Norton and then uninstall all older FF and delete Mozilla folder and then reinstall FF58. Any A/V that is to active will cause installation problems that don't show up til you go to use the program. I use by default W10 Defender and Win Firewall and have no issue install and using FFF58.

It's interesting that you can access some internal pages. Could you try:

New Profile Test

This takes about 3 minutes, plus the time to test a few sites.

Inside Firefox, type or paste about:profiles in the address bar and press Enter/Return to load it.

Click the Create a New Profile button, then click Next. Assign a name like Feb2018, ignore the option to relocate the profile folder, and click the Finish button.

After creating the profile, scroll down to it and click the Set as default profile button below that profile, then scroll back up and click the Restart normally button. (There are some other buttons, but please ignore them.)

Firefox should exit and then start up using the new profile, which will just look brand new.

Can Firefox connect to sites you normally use in the new profile?

When you are done with the experiment, open the about:profiles page again, click the Set as default profile button for your normal profile, then click the Restart normally button to get back to it.

To test if Norton is the problem, disable it. Then start Firefox.

First, I want to sincerely thank all of you who responded to my problem. I still can't use FF 58. Here is what I did: I disabled Norton and started FF with same results, hangs-can't access internet. I left Norton disabled and tried the about:profiles and rcvd same results. I do understand a complete new software release will have issues. (I was a programmer and systems analyst for a major oil company for 20 years). However, I don't have the time to continue jumping through hoops to get FF to run. Reading about the new FF in several different forums, I've discovered I'm not alone. Here's my decision, I'm going to run FF 52.6-(7)-(8)-(?)esr until it is no longer supported. I saw where that will be May or August 2018. After that, if FF still hasn't resolved all the run time problems, I'll be forced to seek another browser that will run.

That is your choice.

Install Older Version Of Firefox {web link} Be sure to read everything here.

If you still want to downgrade, look under; I still want to downgrade. Click the Directory of other versions and languages link. Look for the directory of the version that you want. But, remember that old versions may have security issues.

You should also check out Firefox; Extended Support Release {web link} ESR Notes System Requirements