Solve Firefox Issues

If you are unable to open Firefox, there are two likely reasons: either there an instance of the Firefox profile that you are trying to open already running, or the profile that you are trying to use has been corrupted. The most common error you will see when trying to start Firefox is the first, the "profile in use" error. If you get a "profile is in use" error, this means the Firefox profile is already running or Firefox was improperly shut down the last time it was used. Every time you use a Firefox profile, locks are created for that profile. The locks prevent it from being used elsewhere. You will need to search for and delete any lock files that exist for the profile in order to use it again.

The following steps will help you kill the currently running Firefox processes on your machine, remove the locks on your Firefox profile (if it is running on a different machine), or create a new profile (if the profile you are trying to use can no longer be accessed).

Check to see if Firefox is currently running on your machine

If Firefox fails to start, you will need to kill any Firefox processes that are already running on your machine.

  1. In a terminal, run:
    % ps -ef | grep firefox

  2. Kill any Firefox processes that are running. In a terminal, run:
    % kill <pid>
    Where pid, the process id, is the first number listed in the results returned in step 1.

  3. Try starting Firefox again. If you are still unable to start Firefox, or there were no processes to kill, continue with the next section.

Remove locks from Firefox profile

If you left your Firefox profile running on a different machine or Firefox was previously shut down improperly, you will need to delete the lock files on your profile so you can use it again. The following instructions will show you how to remove the locks from a Firefox profile.

  1. In the terminal, run:
    % lockhunter

  2. Try starting Firefox again. If you are still unable to start Firefox, continue with the next section.

Corrupt Profile

If you are unable to use a profile after deleting the lock files, this means that the profile that you are trying to use is probably corrupt. You can create a new profile and import the bookmarks from your old profile.

Creating a New Profile

  1. In the terminal, run: % firefox -ProfileManager
  2. Click "Create Profile..."
  3. You will see a screen titled "Welcome to the Create Profile Wizard," click "Next"
  4. You will see a screen titled "Completing the Create Profile Wizard," enter the name for your new profile, and click "Finish"
  5. You should now be able to select your new Firefox profile to open

Importing Bookmarks

  1. Go to 'Bookmarks->Organize Bookmarks'
  2. In the box that appears, go to 'File->Import'
  3. Select "From File" and click "Next"
  4. In the file browser that appears, navigate to '.mozilla/firefox/<random_string>.<old_profile_name>/' in your home directory
  5. Select the file named "bookmarks.html" and click "Open"
  6. If Firefox hangs while accessing your directories, let it load for a minute or two.

If you are still unable to start Firefox, email csehelp@umn.edu for further assistance.