Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox.

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

Good morning, Yes what you recommended to start on Safe Mode did fix the problems but on safe mode only. When I start Firefox regular mode, the problem still exist? Any solutions. Thanks

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 so much for your assistance. Oh my god, the culpit was found. This has been giving me trouble for the last few weeks....

Here is the culpit... Enable Right Click and Copy version 2017.4.12 by Afnan Khan.

What a frustrating past weeks this has been. Thank you very very much. Have an awesome day.