Firefox will not start after installing or updating McAfee SiteAdvisor

Firefox may fail to open after:
* installing or updating the McAfee SiteAdvisor Firefox extension, or
* updating McAfee software that includes the SiteAdvisor component

According to MacAfee, the problem is caused by a conflict between SiteAdvisor and automatic proxy configuration scripts in Firefox. To fix this problem, you must start Firefox in Safe mode and uninstall the SiteAdvisor extension. This post describe how to troubleshoot this browser problems. Follow below given

1. Close down Firefox completely: At the top of the Firefox window, click the File menu, and select the Exit menu item.Close down Firefox completely: On the menu bar, click the Firefox menu, and select the Quit Firefox menu item.Close down Firefox completely: At the top of the Firefox window, click the File menu, and select the Quit menu item.
2. In Windows, click Start, open the All Programs list, and navigate to the Mozilla Firefox folder. In the Mozilla Firefox folder, select Mozilla Firefox (Safe Mode).
3, Mac OS:
Hold down the Option key, as you start Firefox.
2.0, Mac OS:
Go to the Utilities directory (in the Applications folder) and open Terminal, then run:

/Applications/Firefox.app/Contents/MacOS/firefox -safe-mode

Go to your Terminal and run:

/path/to/firefox/firefox -safe-mode

3. Firefox should start up with a Firefox Safe Mode dialog.

Note: You can also start Firefox in Safe Mode by clicking Start, selecting Run (or use the Start Search box in Windows Vista) and then entering the following in the text field:

--------------------firefox -safe-mode


4. When Firefox starts in Safe Mode, select the Tools menu at the top of the Firefox window, and select Add-ons. The Add-ons window opens.
5.In the Add-ons window, select the Extensions panel.
6. Select the SiteAdvisor extension.
7. Click Uninstall.
8. If SiteAdvisor is installed as part of a McAfee software package such as McAfee Internet Security Suite, you can selectively remove just the SiteAdvisor component using the McAfee uninstaller. For more information, see the documentation that came with the MacAfee product.