First, I do not have the expertise to project why your version was skipped, as there were more releases of ver 91, as shown in this URL: https://www.thunderbird.net/en-US/thunderbird/releases/ Generally, however, that message appears when you are on the final version of a release. To upgrade, my suggesion is this: - do a full backup of the profile just for safety (I always do this prior to an upgrade) . If on windows, the simple way is to exit thunderbird and copy c:\users\<yourid>\appdata\roaming\thunderbird to anywhere else. - then download 102.0.1 so you benefit from any upgrade fixes. - then repeat for 115.0.1 for further updates - then update to 115.13 - and then repeat the backup process explained above. At this point, you are positioned for the autorelease of 128.

First, I do not have the expertise to project why your version was skipped, as there were more releases of ver 91, as shown in this URL: https://www.thunderbird.net/en-US/thunderbird/releases/ Generally, however, that message appears when you are on the final version of a release. To upgrade, my suggesion is this: - do a full backup of the profile just for safety (I always do this prior to an upgrade) . If on windows, the simple way is to exit thunderbird and copy c:\users\<yourid>\appdata\roaming\thunderbird to anywhere else. - then download 102.0.1 so you benefit from any upgrade fixes. - then repeat for 115.0.1 for further updates - then update to 115.13 - and then repeat the backup process explained above. At this point, you are positioned for the autorelease of 128.

I'll look into it tomorrow, and update you with my findings. Hopefully, someone can explain, why this happens.

Thank you.

According to an article we recently created - https://support.mozilla.org/en-US/kb/upgrading-older-version-thunderbird - version 91 should update fine.

I'll be interested to hear how you do with David's instructions.