Mapping type &1 not supported

What causes this issue?

You tried to execute a mapping of type &V1&. This type of mapping is not
supported.

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?

Check the mapping type in the Integration Repository.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.