invite user error

[cires...@gmail.com]

Deployed an instance on Ubunti 14.04 per:

http://docs.geonode.org/en/master/tutorials/install_and_admin/quick_install.html

When trying to add a new user on the account/invite_user/ page by adding an email, username and clicking "Invite User" results in an Internal Server Error.

Is there a way to fix this, or at least start diagnosing the problem?

Thanks,
Eric