Cannot create users

The create user button is not working. It will sometimes output an error

Only Administrators can create users in Administrators group

Hint

On <nuxeo-create-user> element:

if (!this.user.isAdministrator && this.user.groups.indexOf('administrators') !== -1) 

• this.user is the user in creation, so it is not an administrator (the test should be to principal)
• this.user may not have any defined groups (it is valid) so parte of the boolean expression needs to fisrt validate that there are user groups