Scenario & does not exist

What causes this issue?

The planning scenario that you have entered does not exist.

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?

Use an existing planning scenario or create a new one.
<DS:TRAN.MS31>Create Planning Scenario</>

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.