2669002 - SUM upgrade fails with error 17782 - SAP ASE for Business Suite

SUM upgrade fails and stops  in post-processing phase MAIN_POSTCLEAN/SQLDB_RENAMEIND_SYB with ASE SQL error 17782:

You do not own a table, column, index or partition of that name in the current database.

Output from SQLSTMTSTD.OUT:

EXECUTING /usr/sap/SID/SUM/abap/bin/SAPuptool execdb ../var/SQLDBSCRIPT.TQL
Logging to '/usr/sap/SID/SUM/abap/log/SQLDBSCRIPT.OUT'
1EETQ008 Error message: DBSL error 99 (db code 17782):
1EETQ008 [ASE Error SQL17782][SAP][ASE ODBC
1EETQ009XDriver][Adaptive Server Enterprise]You do not own a table, column, index or
1EETQ009Xpartition of that name in the current database.
1EETQ003 exit code: "20"
SAPup> Process with PID 11008 terminated with status 20 at 20180615120007!

Failing SQL from SQLDBSCRIPT.OUT shows that renaming indexes on the REPOSRC table, via sp_rename, has failed with Error SQL17782.

• SAP Adaptive Server Enterprise (ASE) 15.7 for Business Suite
• SAP Adaptive Server Enterprise (ASE) 16.0 for Business Suite
• SUM 1.0 and 2.0 SP01 PL8

17782 , SUM , SQL17782 , SQLDBSCRIPT.TQL, rename, index, REPOSRC, SQLDB_RENAMEIND_SYB , KBA , BC-DB-SYB , Business Suite on Adaptive Server Enterprise , Problem