Hello, Try disabling graphics hardware acceleration. Since this feature was added to Firefox, it has gradually improved, but there still are a few glitches. You will need to restart Firefox for this to take effect so save all work first (e.g., mail you are composing, online documents you're editing, etc.). Then perform these steps: #Click the menu button [[Image:New Fx Menu]] and select ''Options'' on Windows or ''Preferences'' on Mac or Linux. #Select the ''Advanced'' panel and then the ''General'' tab. #Uncheck '''Use hardware acceleration when available'''. #Restart Firefox and see if the problems persist. Did this fix your problems? Please report back to us! If the problem is resolved, you should check for updates for your graphics driver by following the steps mentioned in these Knowledge base articles: * [[Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems#w_turn-off-hardware-acceleration]] * [[Upgrade your graphics drivers to use hardware acceleration and WebGL]] Thank you.

Sorry, this didn't do it. Thanks for the advice. I am running El Capitan, if that changes anything. Turned off Hardware Acceleration, uninstalled and reinstalled Silverlight. Still getting prompted to install. Still using Chrome until then.