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How to update Thunderbird 78 to 91.6 without losing all my old email?

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  • Last reply by christ1

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My Thunderbird 78.13.0 (64-bit) has asked me to upgrade to 91 for a while. I tried the 91.4 last December, but I lost all my old emails in 7 email accounts in the process. Fortunately I was able to restore my Thunderbird 78 from backup file even though I lost some email that was in the new Thunderbird 91.

Right now due to the strange characters embedded in my email sent from V 78 when other people receive them. It becomes unusable now.

Q1: Do the strange characters appear in the email sent out from Thunderbird 91?

I have @verison.net, @gmail.com, and other business email accounts. I have Windows 10. My Dell has 2 TB SSD C drive for programs and 8 TB D Hard Drive for data. I want to keep all my email in D drive.

I read about the Profile. But I was not successful to upgrade to 91 last December.

Q2: Can you give me Step by step instructions so I won’t make mistakes?

My Thunderbird 78.13.0 (64-bit) has asked me to upgrade to 91 for a while. I tried the 91.4 last December, but I lost all my old emails in 7 email accounts in the process. Fortunately I was able to restore my Thunderbird 78 from backup file even though I lost some email that was in the new Thunderbird 91. Right now due to the strange characters embedded in my email sent from V 78 when other people receive them. It becomes unusable now. Q1: Do the strange characters appear in the email sent out from Thunderbird 91? I have @verison.net, @gmail.com, and other business email accounts. I have Windows 10. My Dell has 2 TB SSD C drive for programs and 8 TB D Hard Drive for data. I want to keep all my email in D drive. I read about the Profile. But I was not successful to upgrade to 91 last December. Q2: Can you give me Step by step instructions so I won’t make mistakes?

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Do the strange characters appear in the email sent out from Thunderbird 91?

I'm not going to guess. There are certainly no strange characters in sent messages here. I doubt that this is a problem of a specific version, but more an issue with your profile.

Can you give me Step by step instructions so I won’t make mistakes?

Close Thunderbird and backup the entire Thunderbird profile prior to the upgrade. https://support.mozilla.org/kb/profiles-where-thunderbird-stores-user-data#w_backing-up-a-profile

Then allow the upgrade when prompted.