3212909 - SUM phase MAIN_POSTCLEAN error: "wrong MT_MODE in SSOI_SYSTSTATE"

 During system update using Software update manager (SUM) in phase "MAIN_POSTCLEAN/TR_MERGELOGS_SPDD_SPAU" , the following error is reported:

PHASE_TR_MERGELOGS_NEW.LOG:

1 ETQ201 Entering upgrade-phase "MAIN_POSTCLEAN/TR_MERGELOGS_SPDD_SPAU"
...
3 ETQ120 PID 20179 execute '/usr/sap/<SID>/<DXX>/exe/tp pf=/usr/sap/trans/bin/TP_DOMAIN_<SID> .PFL merge_buffer_and_logs ALL <SID> -DREAD_TRANSDIR=~ -DTRANSDIR=/usr/sap/trans', output written to '<SUM>/abap/log/TP.ECO'.
3WETQ122  PID 20179 exited with status 16 ''
1EETQ399 Last error code set is: Calling '/usr/sap/BT1/<SID>/<DXX>/tp' failed with return code 16, check
1EETQ399 <SUM>/abap/log/TP.ECO for details
1EETQ204 Upgrade phase "TR_MERGELOGS_SPDD_SPAU" aborted with severe errors

TP.ECO:

EXECUTING /usr/sap/<SID>/<DXX>/exe/tp pf=/usr/sap/trans/bin/TP_DOMAIN_<SID>.PFL merge_buffer_and_logs ALL <SID> -DREAD_TRANSDIR=<SUM>/abap -DTRANSDIR=/usr/sap/trans
This is tp version XXXX
ERROR: wrong MT_MODE in SSOI_SYSTSTATE:''
ERROR: EXIT(16) -> process ID is: 20179

SAP NetWeaver

wrong MT_MODE in SSOI_SYSTSTATE, MT_MODE, SSOI_SYSTSTATE, EXIT(16), tp failed with return code 16 , KBA , BC-UPG-TLS-TLA , Upgrade tools for ABAP , BC-CTS-TLS , Transport Tools , Problem