You need to give more details. When? What was Firefox doing? Did it crash? ----------------- Start '''[https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode Firefox in Safe Mode]''' {web Link} by holding down the '''<Shift><br> ''(Mac Options)'' ''' key, and then starting Firefox. Is the problem still there? ----------------- Separate Issue; Your System Details shows; Installed Plug-ins Shockwave Flash 19.0 r0 Shockwave Flash 16.0 r0 <br>Having more than one version of a program may cause issues. You must remove the older programs. Then get the current full installer. Note: Edge on Win10 does not use ActiveX version but its own Flash. Flash: Grab the uninstaller from here: '''[http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html Uninstall Flash Player | Windows]''' '''[http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-mac-os.html Uninstall Flash Player | Mac]''' Then reinstall the latest version. Flash Player '''Version 19.0.0.185<br>https://www.adobe.com/products/flashplayer/distribution3.html''' '''Note: Windows users''' must download the “Internet Explorer” '''and''' “Plugin-based browsers” installers.