I used to have the exact same issue.

The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information. Note: This will cause you to lose any Extensions, Open websites, and some Preferences.

To Reset Firefox do the following:

1. Go to Firefox > Help > Troubleshooting Information.
2. Click the "Reset Firefox" button.
3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
4. Firefox will open with all factory defaults applied.

Further information can be found in the Refresh Firefox - reset add-ons and settings article.

This worked for me and should work for you.

You can backup your bookmarks, via the Bookmarks Library. For more help on how to do this, please post below.

Hi ComputerWhiz

Thanks for the information and replying to my post, I will try all you have suggested but how do I get my extensions and preferences back. I'm not too bothered about my open websites but I would like to get these back and also my bookmarks. If you can give me some step by step information that would be helpful.

Jumbochick

Backing up files other than the bookmarks from a faulty profile, can cause the issue to return when added back to the current profile.

A good method of remembering what extensions you had, is to write the extension names down. You can then download them again from the Firefox add-ons store.

The only way that I can think of how to remember your preferences, is to do these steps:

1. Open the run window from the Start Menu
2. Type %appdata% and press Run
3. Open the Mozilla folder
4. Open the Firefox folder
5. Open the Profiles folder
6. Open the profile you are currently using
7. Copy prefs.js to another location on your computer's hard drive
8. After resetting Firefox, repeat steps 1-6
9. Copy the old prefs.js file in to the new profile. Replace the new one

I just got off the phone with McAfee Tech Support. As of a few minutes ago, McAfee Site Advisor is NOT supported on the newest versions of Firefox, IE, or Google Chrome!! I was told if I wanted Site Advisor to work I needed to go back and reinstall and use an older version for each of the Browsers.

Not to go against McAfee's judgement, but this is incorrect information.
I currently have McAfee Site Advisor installed and active on Firefox 24.0.

Downgrading to previous version of Firefox or other browsers is an insecure action for McAfee to suggest.

Please try upgrading to Firefox 24.0.

Also, in you add-ons manager does the McAfee Site Advisor extension appear disabled or enabled?
Does the McAfee button in the lower right-hand corner of the Firefox browser display?

Please consider removing McAfee from your computer and then reinstalling.
As long as the subscription current in use, is active, this will not require you to purchase an addition subscription.

WARNING: McAfee account/subscription information may be required to be able to download and install the program.

Thanks ComputerWhiz,

The bad news is EVERYTHING is turned on and should be functional, however the Site Advisor is NOT.... or I should say was NOT.

I just got a follow-up call from McAfee and Site Advisor is now working with newest versions of both Firefox & Google Chrome, but not yet with the newest version of IE.... which doesn't matter to me because I NEVER use IE!!!

I don't use siteadvisor, because it isn't correct at all, it rates bad sites as safe all the time, but anyways, on a local computer of mine, siteadvisor didnt require reinstalling Mcafee since siteadvisor is a seperate program.

Try disabling graphics hardware acceleration. Since this feature was added to Firefox, it has gradually improved, but there still are a few glitches.

You might need to restart Firefox in order for this to take effect, so save all work first (e.g., mail you are composing, online documents you're editing, etc.).

Then perform these steps:

• Click the orange Firefox button at the top left, then select the "Options" button, or, if there is no Firefox button at the top, go to Tools > Options.
• In the Firefox options window click the Advanced tab, then select "General".
• In the settings list, you should find the Use hardware acceleration when available checkbox. Uncheck this checkbox.
• Now, restart Firefox and see if the problems persist.

Additionally, please check for updates for your graphics driver by following the steps mentioned in the following Knowledge base articles:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

• Upgrade your graphics drivers to use hardware acceleration and WebGL

Did this fix your problems? Please report back soon.

If at all possible, please try changing to Windows 7 32-bit.

This can be done from the control panel.

An update for the McAfee Site Advisor was just released.
Go to Firefox add-ons manager and Check For Updates.

Please report back soon.

I just got this problem too. This must be because they are not supporting new versions. Strange because I am not sure why they would take their progress backwards.

Until the Firefox support for the Site Advisor is added again, I recommend using Web of Trust as a substitute. It is almost the same thing.

I will contact them tomorrow and see why they did this and if they will fix it.
I'll write back soon.

I am running Windows XP and Firefox 24.0 and my SiteAdvisor doesn't work either.
My mother is running Windows XP and Firefox 24.0 as well and she can access the SiteAdvisor just fine.
Both versions of McAfee are up-to-date.

I'm going to call the McAfee support team tomorrow and get some support, I will post as soon as I know anything new about this issue.

Sorry for any inconvenience.

I just got off of the phone with the McAfee technical support team.
To fix the issue you need to reinstall the McAfee SiteAdvisor.

This can be done by downloading the free download from this website.

I was able to fix my problem of the McAfee Site Adviser stopping working. I was getting the pop up, it was stopping, slowing, my computer.

I went into the Mozilla "Add-ons Manager" and disabled the McAfee Site Adviser and the Virtual Technician. Since I've done this I haven't had any pop ups and my computer is working very well again. My McAfee AntiVirus is working fine.

If someone has a better idea let me know.

@geoBar9
This really isn't a solution.
The people experiencing this issue don't want to disable this feature of McAfee.

The issue with the McAfee seems to be related to Internet Explorer. Read my below post.

My Call With McAfee

Open Internet Explorer do the following:

1. Select Manage Add-ons from the Tools drop-down menu
2. View the Search Providers
3. Set Google as the default provider
4. Remove all other providers except for Secure Search (McAfee), Google, and Bing
5. Close the Add-on Manager
6. Select the Internet Options from the Tool drop-down menu
7. Set the homepage to the Default or Blank
8. Press Ok
9. Then restart your computer

McAfee SiteAdvisor should then work on all internet browsers and this should prevent the issue from occurring again.
I hope that this will solve your problem.
Please report back soon.

Hello ComputerWhiz

I have tried your recent solution to the site advisor that works when it wants to, twice in case I had done it wrong the first time however I am still experiencing the same issue. I've done everything to try and fix this problem from uninstalling then reinstalling the site advisor to doing the same with firefox, but nothing works for me. Any other suggestions please feel free to guide me but please keep in mind I am not a computer expert so it needs to be in step by step form and as simple as possible.

I recommend contacting McAfee from this site.