Problem

You are trying to start Thunderbird, but it then says it is already running, even though you never had it open.

Cause

This is a known issue that happens when Thunderbird did not close properly.

This often leaves a 'lock' file the application sees and believes it is still running or running in the background somewhere.

This can also happen on Linux systems if a user is logged onto another machine using Thunderbird and then trying to use another linux machine with their networked home directory.

Please follow the solution provided at the following link:

http://kb.mozillazine.org/Profile_in_use

For reference in thunderbird Profile Folder...

Solution

You will want to go into the Profile Folder on your machine...

For Linux

The profile folder is located at ~/.thunderbird/<randomcharacters>.default

For Mac OSX

The profile folder is located at ~/Library/Thunderbird/Profiles/<randomcharacters>.default

For Windows

The profile folder is located at C:\Users\<Windows user name>\AppData\Roaming\Thunderbird\Profiles\<randomcharacters>.default

Remove the lock files...

Remove the following files if they are there:

.parentlock

parentlock

lock

parent.lock

NOTE

For Mac and Linux/Unix users... the '.parentlock' is considered a 'hidden' file. In order to see it, you will need to use the command 'ls -la' to see hiddent files and folders.

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