SAP Message UCS0030 - Task &1 that precedes task &2 in period &3/&4 is not blocked DOCUMENTATION DiagnosisTask &V1&, which precedes task &V2&, has not been blocked yet.Therefore, task &V2& cannot be blocked.ProcedureIf you want to block task &V2&, you first need to block all of the tasksthat precede &V2&.