2594139 - SQL0669N A system required index cannot be dropped

 Upgrade fails with the below error
===========================
2WETP000 08:55:03: Retcode 1: error in DDL statement for "RSDMCHNTAB " - repeat
2EETP345 08:55:15: Retcode 1: SQL-error "-669-SQL0669N A system required index cannot be dropped explicitly. SQLSTATE=42917" in DDL statement for "RSDMCHNTAB "
2 ETP000 --------------- DB-ROLLBACK() ---------------
2EETP334 08:55:15: error in DDL, nametab for "RSDMCHNTAB" not activated
2 ETP301 ----------------------------------------------------------------------
3 ETP361 "0" Shadow-Nametabs activated, DDL executed
2 ETP362 "1" Shadow-Nametab activations failed
2 ETP360 Begin: Act. of Shadow-Nametabs with DDL ("2017/12/19 08:55:03")
2 ETP363 End : Act. of Shadow-Nametabs with DDL ("2017/12/19 08:55:15")

• Db2 LUW 10.5
• SAP Netweaver 7.4/740

UNIQUE, PRIMARY, RSDMCHNTAB , KBA , BW-SYS-DB-DB6 , BW DB2 Universal Database , BC-DB-DB6 , DB2 Universal Database for Unix / NT , Problem