Service provider &1 is not an own service provider

What causes this issue?

Service provider &v1& was determined as the message recipient. Service
provider &v1& is not flagged as an own service provider.
Messages can only be received by service providers flagged as own
service providers.

System Response

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

How to fix this error?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.