Interface mapping Error

Hi,

I am getting an error in Interface mapping for the scenario EDI to Mail. The error is " Mapping program Message Mapping MM_EDI820_TO_HTMLMAIL | urn:cisco-com:test:Verizon_EDI820Invoice_3060_to_E-mail does not match the interface mapping. The number or frequencies of source or target messages for the message mapping are not identical to the number or frequencies of source or target interfaces.".

The same I have tested in the Message Mapping and is working.but not working in Interface mapping.

any idea please..

Thanks

Manmadha