This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

I can't check my e-mail because the same message "A web page is slowing down your browser" pops up over and over again.

  • 4 replies
  • 1 has this problem
  • 1 view
  • Last reply by cor-el

more options

Until Thursday, I was able to check my e-mail using NetZero at webmail.netzero.net. However, since then, every 20 seconds or so, that error message above pops up. I have tried all your troubleshooting suggestions: installing the JavaScript Toggle On and Off and entering the page into the blacklist, and most recently refreshing Firefox. None of this has worked.

Pages with the NetZero domain are the only ones I am having trouble with. Every other page I've visited is fine so far.

The only thing I can think of now is to re-install Firefox completely, and I don't want to do that. Any other suggestions?

Until Thursday, I was able to check my e-mail using NetZero at webmail.netzero.net. However, since then, every 20 seconds or so, that error message above pops up. I have tried all your troubleshooting suggestions: installing the JavaScript Toggle On and Off and entering the page into the blacklist, and most recently refreshing Firefox. None of this has worked. Pages with the NetZero domain are the only ones I am having trouble with. Every other page I've visited is fine so far. The only thing I can think of now is to re-install Firefox completely, and I don't want to do that. Any other suggestions?

All Replies (4)

more options

I am now getting the unresponsive script message with the address of the script: https://ap.lijit.com/sync:4294967295. So I need to know how I can turn it off.

more options

bwbarefoot said

The only thing I can think of now is to re-install Firefox completely, and I don't want to do that.


Note: Firefox comes in three or more folders on all computers. They are;

Maintenance: (Programs Folder) <Windows Only> Firefox itself: (Programs Folder) And two folders in the profile of each user on the computer for each Firefox profile for that user.

If you remove the Firefox folder, the user profiles would not be affected.

Modified by FredMcD

more options

https://support.mozilla.org/kb/Clear+Recent+History#w_how-do-i-remove-a-single-website-from-my-history

Remove History For One Site

Open the History Manager <Control><Shift> H. In the search bar, enter the name of the site. Right-click on one of the listings and select Forget About This Site. This should remove all information, including any settings.

more options

This could be a malware infection.


Do a malware check with several malware scanning programs on the Windows computer.

Please scan with all programs because each program detects different malware. All these programs have free versions.

Make sure you update each program to get the latest version of their databases before doing a scan.

You can also do a check for a rootkit infection with TDSSKiller.


https://support.kaspersky.com/viruses/utility