Regarding Overview Pages generation

I was doing a 6.3 exercise of Rapid Crash course and stuck in creating overview pages of entities of the domain model. In the Domain model, for the entities in the blue color I am able to generate the overview pages but for the department and employee entities the generate overview pages are not allowed. Please suggest me how to resolve the issue.
1 answers

As Per the Crash Course , Employee and Department are Non Persistent Entities – Means volatile tables ,not store in DB.

So for Non Persistent entity you cannot generate Overview Pages . Change the entity to Persistent and then try to generate.