Enter a valid receiver port

What causes this issue?

An entry with the key &v2& is to be inserted in table
&v1&.
The specified receiver port '&v3&' is not valid.

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?

Enter a valid receiver port. Use the Possible entries pushbutton to
display an overview of the receiver ports.

Error message extract from SAP system. Copyright SAP SE.