Solution : https://service.sap.com/sap/support/notes/1152199 (SAP Service marketplace login required)
Key words :
'subtasks' tab page, date-relevant change, cl_dpr_scheduling_service~calculate_dates reason, source program corrections, terms latest start, automatically triggers scheduling, program error, latest dates, latest endsub_objects, affected task
Related Notes :
| 1085640 | Composite SAP Note: Scheduling cProjects |