I had selected multiple messages to delete and accidentally hit the enter button on the keyboard instead of the delete button. Now, I cannot even open Thunderbird without it "failing to respond" and then going to the dialog box and sending a crash report. Every time I re-open the program, the same thing happens. When I close the program and back out completely, it just comes back to the spot with all the open tabs and nothing in the tabs. I cannot close the tabs or get the program to start from the inbox with the messages unopened.