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 *https://support.mozilla.org/kb/Safe+Mode *https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes ---- Make sure that you do not run Firefox in permanent Private Browsing mode (Never remember history). *https://support.mozilla.org/kb/Private+Browsing *Tools > Options > Privacy > Firefox will: "Use custom settings for history" *Deselect: [ ] "Always use Private Browsing mode"