User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.98 Safari/534.13 Build Identifier: firefox beta 4.12 If I start firefox 4.12 the window is frozen and I can do nothing but only close the window. If I want to restart firefox its say that the application is still running. So I have to restart my pc or go to tasks and close firefox. Than I can again startup firefox but it still freeze . Before I had now problem with the beta version 4.8 and less it happens now every time Reproducible: Always Steps to Reproduce: 1.closs my windows and restart the system 2. 3. Actual Results: Still freeze

Please try http://support.mozilla.com/en-US/kb/Safe+Mode

Ok now It works fine, I have done the safe mode and look for the problem. I fond the problem that causses firefox 4.12 to freeze the hole window. the problem is: in EXTENTION " mcAfee SiteAdvisor 3.3 " is causing the problem. for the moment I have disable this function. Can you tell me how to solve this problem

Can you please open about:support (enter it as URL in Firefox) and post the extension category in this bug ? >Can you tell me how to solve this problem Ask mcAfee for a fixed version.

McAfee are working on an updated version of their Site Advisor extension, to prevent the issues it causes with Firefox. To help work out what versions of the extension don't work, it would be useful to know what version you are using. Please can you go to the page "about:support" (type it without quotes in the address bar) and paste the contents of the extension section as a reply here. Thanks!

Reopening since now in the McAfee section, so something for them to sort out.

Went through the issue using the following builds/versions: - latest Nightly build available here: http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2013-03-07-03-09-26-mozilla-central/ - McAfee SiteAdvisor 3.6.0.187 - Windows 7 Home Premium SP1 x64 Opened the latest Nightly build with the McAfee SiteAdvisor enabled and everything worked without any crashes or performance issues.Opened/Closed the browser several times to make sure that the issue isn't occurring intermittently. Philippe, can you reproduce the original issue using the latest Nightly build?