Hi, You can consider to [https://support.mozilla.org/en-US/kb/reset-firefox-easily-fix-most-problems Reset Firefox] which would hopefully resolve the issue.

How does one reset Firefox??

Start Firefox in <u>[[Safe Mode|Safe Mode]]</u> to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance). *Do not click the Reset button on the Safe mode start window or otherwise make changes. *https://support.mozilla.org/kb/Safe+Mode See also: *http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox