Whoops, looks like there was a problem. Please try again , but i have completed all steps in Build a Data Model for a Recruiting App > Create a Self Relationship with the Po

create a case - cleared cache and still get the error  

"Step not yet complete in

Whoops, looks like there was a problem. Please try again." 

I've completed every step - I even had to make sure field security was set for all - you missed that step completely.