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It was so that there was mismatch between business data model and the entity defined therein the project.
MisMatch was there between the TypeDescriptors provided by you in the business data model entity's methods and the entity class file (.cs file).
Setting 'The Identifier represented by this TypeDescriptor' wherever applicable.
Also mark the identifier in the typedescriptor wherever it is encountered. Like you will be having two type descriptors customer_id and customer_name of whichcustomer_id might be identifier so set it up like that.