Hi,
Please check that while creating properties for the entity type there should not be any space in between iv_property_name if it has space it will give you the error 'You are not authorized to display user'.
i have faced the same problem and i have solved it by using above mentioned way.
lo_entity_property = lo_entity_type(
iv_property_name = 'PO Number'
iv_abap_fieldname = 'EBELN' ).
this will throw the above mentioned error since there is space in between PO and Number.
so you can use an underscore over there then it will resolve the issue
like
lo_entity_property = lo_entity_type(
iv_property_name = 'PO_Number'
iv_abap_fieldname = 'EBELN' ).
Thanks,