Inconsistency between DataSource &2 and planning area &1

What causes this issue?

Inconsistencies have been detected between planning area &V1& and the
DataSource &V2& These inconsistencies relate to the InfoObjects.

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.