A large number of emails were deleted from my Inbox for no reason I could discern. I downloaded all the missing folders and files from Carbonite, but I can't get TB to open now. I get this message when I try: "Thunderbird is already running, but is not responding. To open a new window, you must first close the existing Thunderbird process, or restart your system." Since I can't get TB to run, I have no way to close it. Restarting makes no difference. The nice folks at Carbonite confirmed that they had downloaded my emails onto my computer, but said that the Thunderbird problem was not their area of concern. And, if my problem was not solved in 30 days (this occurred about a week ago), they would automatically delete my back-up of these emails from their server.