How To Fix SPXN128 - All external message types must belong to the same package

SAP Error Message - Details

• Message type: E = Error

• Message class: SPXN - Proxy Generation

• Message number: 128

• Message text: All external message types must belong to the same package

What causes this issue?

The assigned message types are based on an external WSDL description and
lie in different packages (&v1& and &v2&).

System Response

Object is inconsistent, because it may be impossible to generate a
unique schema description of the contract or contract implementation.

How to fix this error?

On the 'Objects' tab, all used message types and their packages are
displayed. Navigate to the message type and change the package via
menu->Goto->Object Directory Entry

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.