DataSource does not exist or is not assigned to planning area

What causes this issue?

No entry with the planning area &V1& and DataSource &V2& was found in
the export structure table.

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.