Hi Satyanarayana,
I can think of one scenario when this might happen, you have two Entities A and B and both are associated with each other. So now you create an Object of A and an Object of B (to fill into the association created for A) within your app and you save the Object A (By Commit) by the end of flow. But you probably missed the commit of Object B. This way Object B gets created, gets associated to Object A but when Object A is trying to commit to DB but the associated Object B doesn't exist in DB as it's commit got missed. Make sense?
Check the activities of object creation and see if you do commit the objects. In your case, my best guess is it must be newly created object of ModelSetup or its associated Entity. Thanks!