SAP Message AH420 - Schema &1 contains no schema steps DOCUMENTATION DiagnosisThe following factors could have led to this error message:Schema &V1& contains no schema steps.The schema key is missing in the rate category or the installationSystem ResponseBilling of schema is canceled.ProcedureInsert rate steps in schema &V1& so that the rate layout is complete.Enter the key for a schema which contains the rates belonging to thecontract.