Fix – Thunderbird is already running, but not responding. To open a new window you must close the existing thunderbird process, or restart your system

This is the message I got recently:

Thunderbird is already running, but not responding. To open a new window you must close the existing thunderbird process, or restart your system

The funny thing is, is that thunderbird is NOT running.

Here’s the fix: Navigate to C:\Users\Owner\AppData\Roaming\Thunderbird

and delete the profile.ini

Run Thundbird again and it will recreate a new profile.ini..

WARNING: This will remove your current profile. and you will need to recreate it once firebird starts up.

I had a IMAP account with Google mail which luckly is easily restored since all my email data resides on Google anyway.

Hope that saves you some time. Please leave me a comment below if it helped or if you found an alternative solution.

Talk soon.