-> click Firefox button and click Options -> Advanced panel -> General tab -> Remove Checkmark from Use Hardware Acceleration when available

-> click OK on Options window -> Restart Firefox

Check and tell if its working.

The change made no difference.

Clear Cookies & Cache

• https://support.mozilla.com/en-US/kb/Template:clearCookiesCache

Clear the Network Cache

• https://support.mozilla.com/en-US/kb/How%20to%20clear%20the%20cache#w_clear-the-cache

Troubleshooting extensions and themes

• https://support.mozilla.com/en-US/kb/Troubleshooting%20extensions%20and%20themes

Check and tell if its working.

The only thing that worked was to start in safe mode. Disable add-on only did not work. I do not wish to delete bookmarks or reset tool bars.

I will work around the problem before is reset & delete...

The problem does not occur in Safe Mode

• https://support.mozilla.com/en-US/kb/Troubleshooting%20extensions%20and%20themes#w_the-problem-does-not-occur-in-safe-mode

Check and tell if its working.

All problem testing completed with the same results