2865158 - MAIN_UPTRANS/STARTSAP_PUPG - Unknown return value

SUM is stuck in phase MAIN_UPTRANS/STARTSAP_PUPG, but the system can be started manually without any problems.

SAPup> Starting subprocess in phase 'STARTSAP_PUPG' at 20191028105919

ENV: DBMS_TYPE=hdb
 ENV: PATHEXT=.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC
 ENV: PATH=D:\usr\sap\T1E\SUM\abap\..\jvm\jre\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;D:\usr\sap\XXX\D00\exe;D:\usr\sap\XXX\SYS\exe\uc\NTAMD64;D:\usr\sap\XXX\hdbclient;C:\Users\XXXADM\AppData\Local\Microsoft\WindowsApps
 ENV: RSEC_SSFS_DATAPATH=\\SRV123456\sapmnt\XXX\SYS\global\security\rsecssfs\data
 ENV: RSEC_SSFS_KEYPATH=\\SRV123456\sapmnt\XXX\SYS\global\security\rsecssfs\key
 ENV: SAPSYSTEMNAME=XXX
 *DBENV: dbs_hdb_schema=SAPABC
 ENV: rsdb_ssfs_connect=0
 *DBENV: (auth_shadow_upgrade)
 PWD: D:\usr\sap\XXX\SUM\abap\tmp

EXECUTING <SUM>\abap\..\jvm\jre\bin\java.EXE -cp D:\usr\sap\XXX\SUM\abap\bin\com.sap.hdb.sl.lib.jar;D:\usr\sap\XXX\SUM\abap\bin\com.sap.hdb.core.jar com.sap.hdb.core.main.cmd.HdbCmdMain "HDB_CMD_CLAZZ_NAME=SET_LOG_MODE_NORMAL" "DATABASE_HOSTNAME=<hostname>" "INSTANCE_NUMBER=33" "JDBC_PATH=<SUM>\abap\bin" "READ_FROM_STDIN=TRUE" "DATABASE_SID=XXX" "PORT=33368"
class com.sap.hdb.sl.lib.utils.cmd.clazz.CmdClazzParameterFactory, parameters received. Start execution. Check HdbCmdOut.log and HdbStdout.txt for further information.

....

4 ETQ399 Result of command line call: ''
1EETQ399 Last error code set is: Unknown return value ''
1EETQ204 Upgrade phase "STARTSAP_PUPG" aborted with severe errors ("20191028105918")

HdbCmdOut.log
Thu Oct 31 15:02:44 EET 2019 | com.sap.hdb.sl.lib.instance.DatabaseLogMode | Found log_mode:
Thu Oct 31 15:02:44 EET 2019 | com.sap.hdb.core.main.cmd.HdbCmdMain | End of HdbCmdClazz section: class com.sap.hdb.sl.lib.utils.cmd.clazz.SetLogModeNormal
Thu Oct 31 15:02:44 EET 2019 | com.sap.hdb.sl.lib.connection.sql.JdbcConnection | Closing connection: jdbc:sap://SRHADBNP6:33368 Connect user: System

• SAP HANA DB Version 1.0
• SAP HANA DB Version 2.0

configuration, Unknown return value, STARTSAP_PUPG, exited with status 1 '<UNKNOWN>', '<UNKNOWN>', log_mode , KBA , HAN-LM-UPG-SAP , Upgrade of SAP Systems on HANA , Problem