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?

You can try to disable hardware acceleration in Firefox.

• Options/Preferences -> General: Performance
  remove checkmark: [ ] "Use recommended performance settings"
  "Use hardware acceleration when available"

You need to close and restart Firefox after toggling this setting.

• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

You can check if there is an update for your graphics display driver and check for hardware acceleration related issues.

• https://support.mozilla.org/en-US/kb/upgrade-graphics-drivers-use-hardware-acceleration

Folks, thanks for assistance.

Apologies, I forgot to mention that FF worked fine, BEFORE latest FF update. Problem only arose after update.

Hardware acceleration is off and always has been off.

Starting in SAFE MODE, does indeed fix the problem. But I don't understand, do I have to run in SAFE MODE forever more?

Also, I note that items like the Menu Bar are off by default in SAFE MODE, so, I add it back and other items.

But when I shut down and restart in SAFE MODE again, I have to add them all again.

Just as a test, after starting SAFE MODE, I shut down and tried the regular mode and the problem was still there.

So does the correct operation in SAFE MODE give some clue as to how to fix this and be able to run in regular mode so as to not not lose all my settings?

Many thanks to all for your attention in this matter.

Robert

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.

Hey Fred,

Thanks again. As I mentioned i the initial post, there are no add ons. I did indeed follow your commands with about:addons and it displays a simple notification box that "you don't have any add ons of this type"

Any other ideas my friend ?

Thanks again, Detective Robert

This still sounds hardware acceleration related.

Are you really sure hardware acceleration is disabled?

You can check these prefs on the about:config page:

• layers.acceleration.disabled = true
• layers.acceleration.force-enabled = false

EDIT: If you use a custom theme then try to revert to the default theme.

• "3-bar" menu button or Tools -> Add-ons -> Appearance

In Firefox Safe mode these changes are effective:

• hardware acceleration is disabled (Options/Preferences -> Advanced -> General)
• all extensions are disabled (about:addons)
• default theme is used (no lightweight theme)
• default toolbar layout is used
• xulstore.json is ignored
• userChrome.css and userContent.css are ignored (chrome folder in profile folder)
• JavaScript JIT compilers are disabled

• plugins are not affected
• preferences are not affected

Cor-El an FredMcD,

THANK-YOU for sticking with me on this ! You guys are geniuses.

It was the; layers.acceleration.disabled that was the problem.

All is well now.

Best to both of you, rp108

-)