Make sure that you do not run Firefox in full screen mode (press F11 or Fn + F11 to toggle; Mac: Command+Shift+F). *https://support.mozilla.org/kb/how-to-use-full-screen You can use one of these to set which toolbars to show. *"3-bar" Firefox menu button > Customize > Show/Hide Toolbars *View > Toolbars<br>Tap the Alt key or press F10 to show the Menu Bar *Right-click empty toolbar area You can check for problems caused by a corrupted localstore.rdf file. *http://kb.mozillazine.org/Corrupt_localstore.rdf ---- 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