When I switched my computer on this morning, Thunderbird refused to dowload new emails. Nothing I have tried solves the problem. A message in Crash Reports says: "Shutdown hanging at step XPCOMShutdownThreads. Something is blocking the main-thread". My copy of Thunderbird is up-to-date and accesses two accounts (Gmail and my university account (IMAP)). New emails are missing from both. Any advice on how to solve this problem would be appreciated. Thank you, David Harvey (david.harvey425@gmail.com)