User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:44.0) Gecko/20100101 Firefox/44.0 Build ID: 20160107144911 Steps to reproduce: 10 min. ago I got the popup saying an update wanted to install. I let it as usual, then opened to look at mail. Tried deleting some old stuff and TB froze and locked up. Had to use task mgr to shut it down. Restarted, tried again, same result. Actual results: Froze, locked up, had to use task mgr to kill it and restart, twice. Expected results: Should have functioned as usual with no lock up.
Please start *Windows'* safe mode with networking enabled - win10 http://windows.microsoft.com/en-us/windows-10/change-startup-settings-in-windows-10 Still In Windows safe mode, start thunderbird in safe mode - http://support.mozillamessaging.com/en-US/kb/safe-mode Does problem go away?
After 2nd restart, the issue went away. No idea what it was but TB operates as it usually, excellently does.