https://userapps.support.sap.com/sap/support/knowledge/en/3424030
3424030 - Error "System error in program CL_RSR_HIERARCHY_BUFFER and form _INCL_READ_DB-1-" occurs...
Error "System error in program CL_RSR_HIERARCHY_BUFFER and form _INCL_READ_DB-1-" occurs when executing query or MDX statement.