How To Fix WA161 - The existing subtype &1 is used for the extension

SAP Error Message - Details

• Message type: E = Error

• Message class: WA - Messages from Workflow Event Manager

• Message number: 161

• Message text: The existing subtype &1 is used for the extension

What causes this issue?

You want to extend an object type supplied by SAP by adding an event.
This is not possible. However, there is a subtype that can be extended.
This subtype is used for the remaining steps.
If there are several extendable subtypes, a delegation was entered for
the chosen subtype.

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.