wf_engine.completeactivity returns Activity instance 'SCHEDULING_ELIGIBLE' is not a notified activit

Hi-  11.5.10  EBS question...  We are not running ATP on sellable items.  Each order is put on a hold to prevent scheduling, the planner schedules the order, removes the hold, and progresses the order.  To save the planners from removing holds and progressing we want to remove the hold (no problem, OE_Holds_PUB.Release_Holds works well) and then progress the order with a background process if the date has been entered.

Hold removal, no issue, works fine.

I would have thought wf_engine.completeactivity('OEOL', to_char(l_line_id), 'SCHEDULING_ELIGIBLE', null) would progress the line.

Unfortunately, the API returns:  FDPSTP failed due to ORA-20002: 3133: Activity instance 'SCHEDULING_ELIGIBLE' is not a notified activity for item 'OEOL/570311'.