Result element of container operation must be entered

What causes this issue?

You have not entered a result element as an element of the Workflow
container for the container operation.

System Response

The definition of the container operation contains errors. The Workflow
definition cannot be executed.

How to fix this error?

Please enter the required container element.

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.