When the user tries to delete a draft state entitlement it gives an error "Error has been returned by Hibernate. [Incident# 1457-5054342]" although the entitlement ID did not map to any Host. Check the attachment "Draft state Ent.JPG".
This is an expected application behaviour when there is any maintenance line item liked into entitlement line item. The DELETE statement conflicted with the Primary key REFERENCE constraint between tables.
Unlink the maintenance line item before deleting the Entitlement.