Changes

Shutdown hangs, A shutdown hang is where Thunderbird is still running after you shut it down, do not all have the same cause, even different using exit or some other method. There are many causes for hangs on the same OS. To determine why it Thunderbird is hanging hung, broadly speaking it is helpful to * '''describe what is running in the environment, ''' (described below) * '''obtain a stacktrace, and ''' (described below)* determine a list of '''steps to reproduce. This ''' - which may require some experimentation testing on your part, and we know this is not always possible. But it is important to provide as much of the needed information as you can, and state how often you see the hang (always, rarely, etc).

AlsoYou might not be able to do everything requested here, but it is important to provide as much of the needed information as you can, when and state how often you see the hang (always, rarely, etc).  '''describing the environment''' - When describing the environment of your hang, the answers to these easy questions helps identify the type of hang:# If the problem is reproducible and you have add-ons/extensions installed, does Does the hang happen with Thunderbird started in [https://support.mozillamessaging.com/en-US/kb/Safe+Mode safe mode]? If it can't be reproduced in safe mode then the problem could be an extension. Experiment by disabling add-ons until you find the causeadd-on causing the problem, and contact the add-on author.

# cpu usage - is it usage high (pegged), zero, low, or other?

# are your mail accounts pop, imap, or a combination?# did the computer go into sleep or hibernate while Thunderbird was running?

'''stacktrace''' - If you can, please:* create get a stacktrace using _hang_ instructions in these references and attach stacktrace file to [https://bugzilla.mozilla.org/enter_bug.cgi?product=Thunderbird a bug using _hang_ instructions]: