Hi, You can try to '''Clear Now''' the '''Cache''', and '''Cookies''' with '''Time range to clear''' set to '''Everything''' via '''Tools''' ('''Alt''' + '''T''') > [https://support.mozilla.org/en-US/kb/Clear%20Recent%20History Clear Recent History]. If you have security software (antivirus, firewall etc.) installed, you can try deleting all existing instances of Firefox and its related processes/files including '''plugin-container.exe''' and '''FlashPlayerPlugin_11_5_502_110.exe''' in all the different configuration modules/areas of the security software like process monitoring, sub/spawned process control, virtualization, HIPS etc., in addition to the security software's main configuration panel. Instead create new fully allowed/trusted rules for Firefox + its related processes in all the different modules/panels - a genuine/original Firefox installer as well as all the installed EXEs (Application) and DLLs (Application extension) are digitally signed by Mozilla Corporation (right-click > Properties > Digital Signatures). Even otherwise, some security software may also ask again when Firefox and/or its sub processes are started, and you may be able to allow/trust at that time. Please see [https://support.mozilla.org/en-US/kb/Firewalls this]. [http://kb.mozillazine.org/Firewalls AV/Firewalls Configuration] [https://support.mozilla.com/en-US/kb/Managing%20the%20Flash%20plugin Managing Flash] [http://forums.adobe.com/community/flashplayer Support] [http://forums.adobe.com/index.jspa Forums]