Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options) key, and then starting Firefox. Is the problem still there?

Thank you for your advice. Here is what I did:

I held the SHIFT key down and then I clicked on the Firefox App. A small window opened and gave me two option: 1. Start in safe mode. 2. Refresh Firefox. See attached jpg file.

Option 1. When I chose this option, Firefox started as fast as it should and also loaded web pages as fast as it should!! Great! But, the question is: from now on, do I have to go thru this procedure every time I want to use Firefox? Do I have to customize Firefox every time?

Option 2 - Refresh Firefox (I did not choose this option). It says that if I were to choose this option, all my add-ons and customizations will be removed. Do I need the add-ons and if so, how do I get them back? But most importantly, will this option fix the problem I am having?

Thanks in advance for your kind advice!

Safe Mode is a troubleshooting mode that temporarily turns off hardware acceleration, resets some settings, and disables add-ons (extensions and themes). If the problem goes away, that tells us one thing. If it does not, that tells us something else.

It could be the work of one of your add-ons. Type about:addons<enter> in the address bar to open your Add-ons Manager. Hot key; <Control>(Mac=<Command>)<Shift> A)

In the Add-ons Manager, on the left, select Extensions. Disable a few add-ons, then Restart Firefox.

Some added toolbar and anti-virus add-ons are known to cause Firefox issues. Disable All of them.

If the problem continues, disable some more (restarting FF). Continue until the problem is gone. After, you know what group is causing the issue. Re-enable the last group ONE AT A TIME (restarting FF) until the problem returns.

Once you think you found the problem, disable that and re-enable all the others, then restart again. Let us know who the suspect is detective.

Thank you very very much Mr FredMcD!!!

The add-on that was causing the problem is McAfee WebAdvisor. I left it disabled. Firefox now runs great!!

I have been using McAfee antivirus software for several years now. I wonder if the fact that I disabled the "McAfee WebAdvisor add-on" is going to cause my McAfee antivirus not to function properly?

(I don't even know if the "McAfee WebAdvisor add-on" is part of the McAfee antivirus...  I briefly opened the McAfee App and I did not notice any alert messages...)

The McAfee SiteAdvisor extension has been reported to cause issues. Contact their support for more help

Hello,

I am glad to hear that your problem has been resolved. If you haven't already, please select the answer that solves the problem. This will help other users with similar problems find the solution more easily.

Thank you for contacting Mozilla Support.