What are you using for ad blocking?

Security Issue: Update your Flash Player Version 18.0.0.232
https://www.adobe.com/products/flashplayer/distribution3.html Note: Windows users must download the “Internet Explorer” and “Plugin-based browsers” installers.

Note: Edge on Win10 does not use ActiveX version but its own Flash.

See if there are updates for your graphics drivers https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

There are other things that need attention.

The System Detail list shows an outdated Shockwave Flash 10.0 r45 plugin.

You can find the installation path of all plugins on the about:config page.

• http://kb.mozillazine.org/Issues_related_to_plugins#Identifying_installed_pluginugins

You can uninstall the current Flash player version and (re)install the latest Flash version.

See this about uninstalling Flash players:

• http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html

Note that this will remove all installed Flash players.

You can find the latest Flash player versions for Firefox on this page:

• http://www.adobe.com/special/products/flashplayer/fp_distribution3.html