SAP Message RSRV290 - Unknown error when deactivating aggregates; execution terminated

Diagnosis When deactivating the affected aggregates, an unknown error occurred.It is possible that a part of the affected aggregated were alreadydeactivated. The X/Y table is not rebuilt. Procedure Check the log to see if there are notes referring to the cause of theproblem. If you cannot find a solution, ask your SAP consultant or sendan error message to SAP.