Diagnosis
The following situation leads to this error:

• This activity has a subsequent event task executed synchronously

. This event must not be deactivated.

• The activity has been declared rejectable (processing can be rejected)
and therefore the event processing rejected
is likewise not deactivated.

• If it involves a wait step, the event wait step terminated must
not be deactivated.

System Response
The event task executed synchronously and wait stepterminated must never be deactivated, the event processingrejected only if you do not set the indicator processing can berejected.