Reported Problem: Mingle project imports fails with the error message "undefined method `ancestors' for nil:NilClass"
[2011-11-28 11:32:09,903] [process_project_imports] [com.thoughtworks.mingle] ERROR Unable to import project.
undefined method `ancestors' for nil:NilClass
If you suspect a serious problem, please run Mingle with log level set to DEBUG to see the full detail of this error.
Solution: The issue is caused when there is a mismatch in the login name of a user on the two instances but the email address is the same. To solve the problem change the login name to be the same on both instances.