Join the club MasterThief.

Lots of people are having the same problem.

All using Firefox 3.6*, I think.

• https://support.mozilla.com/en-US/questions/832793

   * https://support.mozilla.com/en-US/questions/769742
   * https://support.mozilla.com/en-US/questions/777912
   * https://support.mozilla.com/en-US/questions/810895
   * https://support.mozilla.com/en-US/questions/812162
   * https://support.mozilla.com/en-US/questions/832845
   * https://support.mozilla.com/en-US/questions/832865
   * https://support.mozilla.com/en-US/questions/832941
   * https://support.mozilla.com/en-US/questions/832985
   * https://support.mozilla.com/en-US/questions/833021
   * https://support.mozilla.com/en-US/questions/833037
   * https://support.mozilla.com/en-US/questions/833058
   * https://support.mozilla.com/en-US/questions/833109
   * https://support.mozilla.com/en-US/questions/833195

I had no luck with other alleged solutions, and one I tried caused Adobe Flash Player to screw up (as others have reported elsewhere). Here’s what I did to help alleviate (not solve) the Plugin Check problem:

1. Type “about:config” (without quotes) in your web address box and hit return. This should take you to a (not-so-secret) Firefox configuration page that lists the many Firefox settings.

2. If you first get a warning message, click the "I'll be careful, I promise!" button. Do be careful not to mess up any settings unintentionally. (The worst scenario might be that you have to re-install Firefox—do you have your preferred Firefox version [e.g., 3.6] setup file saved somewhere? You may want to download it first, to be safe.)

3. Once on the about:config page, in the “Filter” box at the top type “plugins.update” (again, no quotes). This should reduce the visible list down to only two (or so) settings. (Don’t worry--doing this does not change or remove anything, just makes the list you see more manageable. The full list will still be there if you remove the filter.)

4. Double-click on the “plugins.update.url” setting line to change the address “https://www.mozilla.com/%LOCALE%/plugincheck/” to anything else you want, for example “http://www.google.com”, or “http://my.ebay.com”, or your homepage address. Then exit Firefox (there is no "save" action needed).

Now when you start Firefox again you will have two tabs, one with your homepage and one with that other address in place of the Plugin Check page. This doesn’t solve the problem, but at least you do not have to look at the annoying Plugins Check page. (You can always put the original address back in the about:config page if you do want to see the Plugin Check page.) If you make the address your homepage, you’ll have two homepage tabs and can ignore or delete the second one.

Let’s hope a real solution (for FF 3.6 users) is found soon. I suspect that Mozilla wants everyone to switch to Firefox 4, which may be the real answer. Annoying.

I run FF 4 and am having the same problems with no solutions, I have tried the ones here.

I was having the same problem Master Thief. I followed steps one through three that tps5352 listed above. I found the setting line "plugins.update.notifyUser" and clicked it to set the value to false. I then restarted my browser, and the second "Plugin Check" tab did not open. I tested the theory again by setting the value to true- the tab opened again. Set it back to false, no tab.

Hope this helps.

Khaidee, thanks but that doesn't work for me. The default setting for that line (on my PC) is "false." Changing back and forth from "false" to "true" and back makes no difference. The Plugin Check page still comes up. In fact, when I change it to "true" and exit Firefox (FF), upon restarting FF the value is back to being false!!?? What does THAT mean?

BTW, blocking the Plugin Check page address (using my Linksys router software) does not really help. Yes it's blocked. But FF still attempts to create a second tab and the page just gets hung up. Still annoying.

The only thing that partially helps for me is to put a new address (e.g., my homepage) in the “plugins.update.url” line in the FF configuration page "about:config" (as outlined in my post above).

It reminds me of porn sites. Each hit is money in the till. It doesn't matter if it is true or false. Ticked off going back to IE.

You can correct this issue by forcing the file blocklist.xml to update or wait until Firefox updates the file.
That update will remove the severity="0" flags in the file that cause the problem.

See:

• /questions/832793?page=2#answer-198407
• http://forums.mozillazine.org/viewtopic.php?p=10899869#p10899869

• Bug 663722 - The blocklist output is including severity="0" where it shouldn't be