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

A blank gray box won't go away...why not? How can I get rid of it?

  • 3 majibu
  • 2 wana tatizo hili
  • 4 views
  • Last reply by lmahovetz

more options

Every time I open Firefox, a gray box (about 1in x 1in) appears in the near upper left hand corner of my screen. When Firefox is open (and not hidden) the gray square covers any window that it is located over - this will included any non-Firefox applications. Only when Firefox is exited or hid will the gray square disappear. Please help!! I'd like this square to be gone.

Every time I open Firefox, a gray box (about 1in x 1in) appears in the near upper left hand corner of my screen. When Firefox is open (and not hidden) the gray square covers any window that it is located over - this will included any non-Firefox applications. Only when Firefox is exited or hid will the gray square disappear. Please help!! I'd like this square to be gone.

All Replies (3)

more options

This could be a feature of a Firefox add-on. A standard diagnostic to bypass interference by extensions (and some custom settings) is to try Firefox's Safe Mode.

First, I recommend backing up your Firefox settings in case something goes wrong. See Back up and restore information in Firefox profiles. (You can copy your entire Firefox profile folder somewhere outside of the Mozilla folder.)

Next, restart Firefox in Firefox's Safe Mode (Diagnose Firefox issues using Troubleshoot Mode) using

Help > Restart with Add-ons Disabled

In the dialog, click "Start in Safe Mode."

If the site works correctly, this points to one of your extensions or custom settings as the problem.

To further disable add-ons, you can try here:

Tools > Add-ons > Plugins category

Any change?

more options

You can also try to remove the Firefox plist file (org.mozilla.firefox.plist).

Go to "~/Library/Preferences" and remove the plist file for Firefox (org.mozilla.firefox.plist)


You can also check for problems with the localstore.rdf file.

more options

Yes it worked thank you!!! I found the add-on that was triggering it and disabled it!