Fix Firefox hangs or not responding in Delaware

When Firefox hangs, it stops responding to your clicks and keystrokes and doesn’t seem to be doing anything. Also, a “(Not Responding)” label is displayed in the title bar and the mouse cursor becomes a spinning wheel when it’s over the Firefox window. This article gives you solutions to Firefox hangs depending on when they happen.

Firefox hangs at random times

If Firefox seems to hang randomly and not after a specific action (for example, downloading a file or quitting Firefox), try the solutions in this section.

Create a new places database

If hangs are periodic, it may be caused by a corrupted places database.Information: The “places” files store the annotations, bookmarks, favorite icons, input history, keywords, and browsing history (a record of visited pages).

To create a new places database, do the following:Warning: This will clear your browsing history and remove bookmarks of the day.

  1. Open your profile folder:Click the menu button  , click Help and select Troubleshooting Information. The Troubleshooting Information tab will open.
    • Under the Application Basics section next to Profile Folder, click on Open Folder. Your profile folder will open.Note: If you are unable to open or use Firefox, follow the instructions in Finding your profile without opening Firefox.
  2. Click the Firefox menu  , then click Exit.Wait until Firefox has completely quit.
  3. In the Firefox profile folder, find and rename the files places.sqlite to places.sqlite.old and places.sqlite-journal to places.sqlite-journal.old (if it exists).
    • To rename a file, right-click on it and select rename from the menu. Then add .old to the end of its name.
  4. Finally, reopen Firefox.
    • When Firefox reopens it will create a new places database. Your browsing history will be lost but Firefox will automatically import your bookmarks from the most recent backup file.

Turn off hardware acceleration

With some graphics card and graphics driver setups, Firefox may hang when using hardware acceleration. You can try turning off hardware acceleration to see if it fixes the problem.

  • Click the menu button  and select Options.
  • Select the General panel.
  • Under Performance, uncheck Use recommended performance settings.
    Additional settings will be displayed.
  • Uncheck Use hardware acceleration when available.
  • Click the Firefox menu  , then click Exit.
  • Start Firefox the way you normally do.

Delete duplicated Session Restore files

Firefox may be slow to respond or hang if multiple copies of its Session Restore file have been created:

  1. Open your profile folder:Click the menu button  , click Help and select Troubleshooting Information. The Troubleshooting Information tab will open.
    • Under the Application Basics section next to Profile Folder, click on Open Folder. Your profile folder will open.
  2. Click the Firefox menu  , then click Exit.
  3. Locate and delete the sessionstore.js file and any copies, such as sessionstore-1.jssessionstore-2.js.

Change the PAC implementation

If you’re using a proxy auto-config file (PAC), Firefox may hang when you attempt to load sites that don’t exist or that you haven’t opened recently. To determine if you use an automatic proxy configuration file:

  1. Click the menu button  and select Options.
  2. In the General panel, go down to the Network Settings section.
  3. Click Settings…. The Connection Settings dialog appears.
  4. If Automatic proxy configuration URL is selected, you are using an automatic proxy configuration file. Do not disable this setting, which will prevent you from accessing the Internet. Instead, provide this workaround to your network administrator.
  5. Click Cancel.

Firefox hangs after using it for a long time

Update Firefox

The latest Firefox versions includes improvements in memory usage, especially during long sessions. Update Firefox to the latest version.

Restart Firefox

Firefox may hang if left open for long periods of time. To fix the issue, restart Firefox.

If you regularly leave Firefox open so that you return to where you left off, you may want to use Firefox’s Session Restore feature.

Firefox hangs when downloading files or saving images

If Firefox hangs when you attempt to download a file or save an image, try these solutions:

Clear download history

Firefox may hang when downloading files if your download history has grown too large. To clear the download history:

  1. Click the Downloads button  on the toolbar, if it’s available, or else click the Library  button and click Downloads from the menu.
  2. Click Show All Downloads at the bottom of the Downloads panel. The Library window will open.
  3. Click the Clear Downloads button at the top of the Library window.
  4. Download some sample files to see if the hanging has stopped.

Choose a different download folder

Firefox may hang if the last download folder location (e.g. a shared volume or USB drive) is no longer available. To fix this:

  1. Click the menu button  and select Options.
  2. Select the General panel.
  3. Under Downloads, select Save files to and click the Browse button.
  4. In the Choose Download Folder window, choose a new folder location.
  5. Close the about:preferences page. Any changes you’ve made will automatically be saved.

See if you are now able to download files or save images. If this works, you can go back to your Firefox settings, if you wish, and select Always ask me where to save my files.

Firefox hangs when you quit it

Sometimes when you close Firefox, it may stop responding and remain in memory, even though no Firefox windows are open. This can prevent Firefox from working properly the next time you open it or you may see a “Close Firefox” dialog box with an error message, Firefox is already running, but is not responding.