Field DOCTYP will not be able to be completed

What causes this issue?

You have entered a port in the partner profile that uses the control
record in a release prior to 3.0. In this control record, there are no
fields for basic type and extension, but only an 8-character field for
identification of the transferred structure (EDI_DC-DOCTYP).
The basic type (and possibly extension) must therefore be converted
into an 8-character name.
However, no conversion could be found in the relevant table.

System Response

Outbound processing cannot process this combination correctly.

How to fix this error?

Create a conversion entry or use another port version.

Error message extract from SAP system. Copyright SAP SE.