No activity for resource determined. &1 &2 &3

What causes this issue?

No suitable activity can be determined for the transferred resource.

System Response

The action was terminated.

How to fix this error?

Check whether the resource is assigned to the active planning version.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.