Interestingly, this seems to have just happened for about 30 messages. Perhaps during the upgrade. I haven't seen any of these problems afterwards and there were not Thunderbird updates. Odd.

It doesn't happen to all incoming emails but especially after I have deleted an email then, clicking on a recent email below in the Inbox, I get the correct Subject showing but the content of the deleted email. Using Repair just deletes the (previously) undeleted one so that's lost forever!!! Sometimes the jumble comes if I just click quickly between emails in the Inbox. There seems no common theme to the type of email being corrupted: it has happened to simple one-line text messages as well as full picture-rich pages. I'm also being frequently prompted to download the latest version of Thunderbird - which I have already installed and really wish I hadn't!

Have now installed v102.0.1 and thought that might have corrected this issue but - it hasn't.

Deleting one email, going on to view another and then another in the Inbox list and the content of the 3rd one has been lost and replaces by the HTML of the one I deleted!

Using Repair removes the undeleted one from the Inbox list altogether. So I am now missing an email that I have been sent.

This is preposterous! v102 should never have been released in this faulty state.