Source field &1-&2 for mapping &3 not found (position:&4)

What causes this issue?

Source field &V1&-&V2& for mapping &V3& not found (position: &V4&).

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?

Go to the tab 'Rule Assignment' of the embedded specification and check
the settings done for domains, data elements, and table fields.
Assign a transformation rule with suitable parameters to table field
&V3& at position &V4&, or, exclude the table field.
After that re-execute this activity again.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.