Proposed reference date not maintained for completn of notification type

What causes this issue?

The PM notification type table does not contain a default reference
time for completing the notification for this particular notification
type.

How to fix this error?

By means of the customizing function, maintain the reference time to be
to be proposed as the completion time for the notification:
malfunction start
malfunction end
notification start
notification end

Error message extract from SAP system. Copyright SAP SE.