Mail crashing - "Cannot set MFGmailLabelStore as data source"

[Cougarcat]

I had this bug in the GM and it went away, but today it came back, on both a 10.11.1b MacBookPro and a 10.11.0 desktop. Mail will crash within a minute of launching. The error is:
*** Terminating app due to exception while holding database lock 'NSInternalInconsistencyException', reason: 'Cannot set MFGmailLabelStore as data source for message.'
abort() called

 

[dianeoforegon]

Quit Mail
In your User's Library/Containers folder, drag com.apple.mail folder to the Desktop.
Log out/in
Open Mail and see if problem goes away.

If no, then test in a new User. Testing in a new User will quickly tell you if the problem is system wide or if it's your User's folder that contains the problem.

 

[Ravenis]

Remove the account and re-add it