Thunderbird is stuck with an overlay thta won't close or accet input, "This site attempts to identify iitself with invalid information." I'M STUCK!
I added a new email account, dalvord@kgcomm.net, at a site on Register.com. Though it populated the new inbox, Thunderbird then put up a window with the quote above, asking to get a security certificate. But no matter what I click, including Cancel, the window pops up again immediately, and I can' t even close Thunderbird or do any other action.