Hello,I am Pete, and I'll be happy to assist with your question today.
What did you download to the computer, please?
Ok, you will need to uninstall and reinstall it again.
Select Mozilla Thunderbird and click on uninstall. Then download a fresh version from the link below. Make sure you select the correct language and OS.
If you are downloading from the official Thunderbird site, the language selection will be offered when you download.
Your payment for the remote assistance has not gone through successfully so I am unable to connect.