I received an error 'Invalid Code:3035: NAD:16', what does it mean?

I received an error 'Invalid Code:3035: NAD:16', what does it mean?

This means Segment NAD at Line 16 of EDI which has an invalid code. In this case this refers to Party Details under Invoice. There is one with Party Type 'IM' which is not a valid party type under the Invoice section.