You are talking to fellow users offering their free time to help a fellow user and not developers. We do not fix code, we did not update your computer, but we can help to find out what was going on and in many cases provide info on how to prevent it from reoccuring. To do that, information is required to understand your setup, that's why we ask questions.

I asked twice for you to supply specific information to find out what was happening in your profile folders. Zenos and Matt also pointed this out. You have still not answered those questions.

re: My anti virus would likely take out an email but not a whole folder! Unfortunately, that theory is wrong. When you see a 'folder' in your Folder Pane eg: 'Saved' in Local Folders, that is actually an mbox text file stored in the profile folders. Emails are written to an mbox file, one after the other in the order downloaded or saved. So it looks like one long document and each email is like a new paragraph. If AV is scanning Thunderbird files on startup and locates something it does not like in that file, then the whole file can be effected. This often shows an indexing file unaffected but the mbox file gone. Providing the information would have shown this, if it was the case.

I was also trying to find out if you had more than one 'Local Folders' mail account. Perhaps, the first one could not be located for some unknown reason and a second was created - maybe that first one still exists. This info would have been provided to all those who were trying to help you, if you had answered questions. I also wanted to find out what 'Local directory' was being used for Local folders as this may also have given clues as to what may have occurred.

Please assume that if fellow users of thunderbird ask for information, then it is because it is needed in order to help you.