Error while generating the Odata Service for External Odata Services

Hi ,

I am getting an Error while generating the Odata service for external odata service as "Error while fetching the source metadata".

HTTP Destination              - ODATA_ORG

Service Namespace           - V3/Northwind

Service Name                    - Northwind.svc

Model Provider Class         - ZCL_NORTHWIND_MPC

Data Provider Class          - ZCL_NORTHWIND_DPC

Model Name and Version   - ZNORTHWIND_MPC

Service Name and Version - ZNORTHWIND_SRV

While doing a connection test to the RFC destination it works fine.

Any prerequisites before generating the odata service in SAP gateway other than RFC Destination .

Regards,

Dwity Krushna