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Thunderbird is already running, but is not responding. The old Thunderbird process must be closed to open a new window.

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  • 4 have this problem
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  • Last reply by sfhowes

msturgis
msturgis
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I'm running Windows 11 Pro on a new laptop and had to remove and reinstall Thunderbird ... this is the 3rd time and I still have this same problem ... IT WON'T START OR RUN AT ALL. All I get is a "Close Thunderbird" popup saying, "Thunderbird is already running, but is not responding. The old Thunderbird process must be closed to open a new window."

As best as I can determine there are no other instances of Thunderbird running.

I "Googled" the problem but found nothing that has worked.

I need my Thunderbird back. Anyone ... Please tell me how to fix this problem.

Thanks Maureen

I'm running Windows 11 Pro on a new laptop and had to remove and reinstall Thunderbird ... this is the 3rd time and I still have this same problem ... IT WON'T START OR RUN AT ALL. All I get is a "Close Thunderbird" popup saying, "Thunderbird is already running, but is not responding. The old Thunderbird process must be closed to open a new window." As best as I can determine there are no other instances of Thunderbird running. I "Googled" the problem but found nothing that has worked. I need my Thunderbird back. Anyone ... Please tell me how to fix this problem. Thanks Maureen

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sfhowes
sfhowes
  • Top 10 Contributor
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Try removing the profile lock file:

https://kb.mozillazine.org/Profile_in_use#Remove_the_profile_lock_file