Hello everyone, In 09/15/2016 Windows notified an update. I turned off my computer in order to accomplish the update. In the next day (09/16) I turned on my computer and ALL Local Folders disappeared! I had more than 30 folders with years of e-mails stored on this computer. At first, I have verified the local folder at: C:\Windows.old\Users\dsouza.JACUNDA\AppData\Roaming\Thunderbird\Profiles\2bbcgjn1.default\Mail\Local Folders\ And all ".msf" files had dissappeared. However, here's my light at the end of the tunnel. Thunderbird's has a search box at its top right-hand corner. I entered the subject of one of the e-mails that was in one of the local folders that disappeared. I was surprised that Thunderbird could show me all mail messages (both received from and sent to) in the results with that subject! I did similar searches on a number of other subjects who also were in the disappeared local folders and in each case, relevant mail messages (some even with their attachments) were displayed. This leads me to believe that the lost folders are, in fact, not lost, but somehow just misplaced. The funny thing is that the search results shows all local folders names and the number of messages that were in them. And whenever I make a search, ".msf" files are automatically created in the Local Folders, with the name of the lost folder involved on the search, but with 0 KB! Do you have any idea of what is going on??? A salute from Brazil (I have asked this in the Portuguese forum, without success). Diego