2692680 - Error in MAIN_UPTRANS/SUCCCHK_PROD: 2EETQ399 Change request 'SAPK-<ver>INCTSPLGN' not removed from buffer.

In MAIN_UPTRANS/SUCCCHK_PROD, Software Update Manager (SUM) tool errors out with below error:

PHASES.LOG

1 ETQ201 Entering upgrade-phase "MAIN_UPTRANS/SUCCCHK_PROD" ("20180809151745")
2 ETQ367 Connect variables are set for standard instance access
4 ETQ399 System-nr = '40', GwService = 'sapgw40' Client = '000'
4 ETQ399 Environment variables:
4 ETQ399 dbs_ora_schema=SAPSR3
1 ETQ200 Executing actual phase 'MAIN_UPTRANS/SUCCCHK_PROD'.
1 ETQ399 Phase arguments:
2 ETQ399 Arg[0] = 'CHECK_SIDBUFFER;CHECK_CVERS'
2EETQ399 Change request 'SAPK-<version>INCTSPLGN' not removed from buffer.
2 ETQ399 Empty putsteps - configuring at least parallel batches and main import processes.
2 ETQ399 Distribute 12 parallel processes to 2 tp and 6 R3trans.
2 ETQ399 Requested task ID is 'READ_CVERS'.
3 ETQ399 Generated TQL file 'CVERSDUMP.TQL' with 2 SQL statements, log file 'CVERSDUMP.TMP'.
2 ETQ399 Distributed 0 statements, 2 actual ones are written to TQL files.
4 ETQ276 Executing SQL-script "CVERSDUMP.TQL"
3 ETQ120 20180809151745: PID 31667 execute '~/bin/SAPuptool execdb ../var/CVERSDUMP.TQL', output written to '/usr/sap/<SID>/SUM/abap/log/SQLSTMTSTD.OUT'.
3 ETQ122 20180809151745: PID 31667 exited with status 0 (time: 0.0/ 0.0/ 0.0/179MB real/usr/sys/maxmem)
3 ETQ399 Reading selections from 'CVERSDUMP.TMP'.
4 ETQ399 Read 6 entries for table 'LIST'.
4 ETQ399 Read 27 entries for table 'LISTFULL'.
4 ETQ010 Date & Time: 20180809151745 
1EETQ399 Last error code set is: 1 transports are still in the buffer (see phase log PHASES.LOG for details)
1EETQ203 Upgrade phase "SUCCCHK_PROD" aborted with errors ("20180809151745")

SOLUTION MANAGER 7.1 - 7.2

 MAIN_UPTRANS/SUCCCHK_PROD, SAPK-74028INCTSPLGN, SAPK-75028INCTSPLGN, , KBA , BC-UPG-TLS-TLA , Upgrade tools for ABAP , Problem