Message type & could not be converted

What causes this issue?

You have entered a port in the partner profile that uses the control
record for Release 3.0/3.1. In this control record, the field for the
logical message type is only 6 characters long.
There must therfore be a conversion of the long name &v1& into a name
with a maximum of 6 characters. 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.