You can check for problems caused by recent Flash updates and try these: *disable a possible RealPlayer Browser Record Plugin extension for Firefox and update the RealPlayer if installed *disable hardware acceleration in the Flash plugin See also: *http://kb.mozillazine.org/Flash#Troubleshooting 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 or otherwise make changes. *https://support.mozilla.org/kb/Safe+Mode *https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes Also make sure that your security software (firewall, anti-virus) isn't blocking such streamed content.

Check your Flash Player settings - [http://forums.adobe.com/message/4468493#TemporaryWorkaround Adobe Community: How do I troubleshoot Flash Player's protected mode for Firefox? ] Worked for me. Also do check Firefox Support Forum article: [https://support.mozilla.org/en-US/questions/959450 Firefox slow on certain sites]

please [[Update Firefox to the latest version|update firefox]] and [https://www.mozilla.org/en-US/plugincheck/ your plugins].