Often, closing Thunderbird returns this additional error: If you have these problems, here’s what might be happening and what you can do to fix these issues.
Causes of Thunderbird Not Responding
If Thunderbird refuses to start and returns an error about an existing Thunderbird process, it’s because Thunderbird thinks your profile is in use. The cause might be a stale profile lock that was left after Thunderbird crashed. This means Thunderbird didn’t close properly or correctly clean up temporary files. Additional processes are running in the background and Thunderbird is confused, frozen, and unable to open. Another cause might be that Thunderbird is running on another computer. Thunderbird can’t run on more than one computer at the same time with the same profile.
How to Make Thunderbird Start Again
If Thunderbird is running but not responding, or it’s saying that your profile is in use, here are the steps you should try.
