Try The Refresh feature (called "Reset" in older Firefox versions) can fix many issues by restoring Firefox to its factory default state while saving your bookmarks, history, passwords, cookies, and other essential information.

Note: When you use this feature, you will lose any extensions, toolbar customizations, and some preferences. See the Refresh Firefox - reset add-ons and settings article for more information.

To Refresh Firefox:

1. Open the Troubleshooting Information page using one of these methods:
   • Click the menu button , click help and select Troubleshooting Information. A new tab containing your troubleshooting information should open.
   • If you're unable to access the Help menu, type about:support in your address bar to bring up the Troubleshooting Information page.
2. At the top right corner of the page, you should see a button that says "Refresh Firefox" ("Reset Firefox" in older Firefox versions). Click on it.
3. Firefox will close. After the refresh process is completed, Firefox will show a window with the information that is imported.
4. Click Finish and Firefox will reopen.

Do you recall in more detail what you installed? Would it be listed in your downloads (Ctrl+j) or in your history?

To test with extensions disabled, you can restart in Firefox's Safe Mode:

If Firefox is not running: Hold down the Shift key when starting Firefox. (On Mac, hold down the option/alt key instead of the Shift key.)

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" Help button > Restart with Add-ons Disabled
• (menu bar) Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

It was a project scheduling program called Smart Sheets.

No improvement after running with extensions disabled.

Hmm, could be a corrupted settings file. You can rename the file and have Firefox rebuild it. Here's how:

Open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" Help > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, on the Profile Folder row, click the "Open Folder" button. This should launch a new window listing various files and folders in Windows Explorer.

Leaving that window open, switch back to Firefox and Exit, either:

• "3-bar" menu button > Exit
• (menu bar) File > Exit

Pause while Firefox finishes its cleanup, then rename xulstore.json to something like xulstore.old. If you see a file named localstore.rdf, rename that one to localstore.old.

Start Firefox back up again. Do windows display normally again?

That mini-reset will normally hide the menu bar and bookmarks toolbar. You can use one of these methods to show the toolbar list and select the desired bars there:

• right-click (on Mac Ctrl+click) a blank spot on the tab bar (or the "+" button)
• (menu bar) View > Toolbars
  On Windows, tap the Alt key to activate the menu bar temporarily.
• in Customize mode > Toolbars button (see: Customize Firefox controls, buttons and toolbars)

To turn on the Bookmarks Toolbar, Menu Bar, or other bars, click it on the list.

Any improvement?

Is that application installed as an extension in Firefox?

Try to rename/remove xulstore.json and if present delete localstore.rdf in the Firefox profile folder with Firefox closed. If the application is an extension then first try this with the extension disabled.

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Not an extension. Renaming localstore and xulstore did not help.

Do you have Firefox set to restore your previous session automatically at startup?

Some users reported the Bookmarks Toolbar a few moments after startup, and one of them reported that it was fixed by:

• Turn off the setting to restore previous session automatically at startup*
• Exit Firefox and start it up again
• Restore previous session from the "3-bar" menu or on the menu bar, the History menu
• Turn automatic session restore back on*

* on the Options page

Never mind...I backed up my profile uninstalled and reinstalled and all is back to normal.

Thanks for the help