3366356 - MAIN_NEWBAS/HANA_DEPLOY_UPG phase hangs and job RDDIMPDP fails with ERROR_MESSAGE

Upgrade via SUM hangs in phase MAIN_NEWBAS/HANA_DEPLOY_UPG.

In transaction SM37, it can be seen that the job RDDIMPDP fails with following log entries:

Job Log Overview for Job:    RDDIMPDP / <Job_number>

 Date       Time     Message text                                                  Message class Message no. Message type

 14.08.2023 09:17:56 Job RDDIMPDP <Job_number> started                                    00           516          S
 14.08.2023 09:17:56 Step 001 started (program RDDIMPDP, variant , user ID DDIC)      00           550          S
 14.08.2023 09:17:56 Program RDDIMPDP is running in client 000                        PU           050          S
 14.08.2023 09:17:56 The language <Z> is not installed                                  BT           274          E
 14.08.2023 09:17:56 Job canceled after system exception ERROR_MESSAGE                00           564          A

 In transaction SM21,

14.08.2023    09:17:56    <host_SID_Nr>    BTC    092    000    DDIC    @5B\Qwarning@    EF2    BP_STEPLIST_EDITOR: Invalid step values (step 1) found. Reason:
14.08.2023    09:17:56    <host_SID_Nr>    BTC    092    000    DDIC    @SR\Qinformation@    EJ8    > The language with the key <Z> is not installed
14.08.2023    09:17:56    <host_SID_Nr>    BTC    092    000    DDIC    @5B\Qwarning@    EFN    BP_JOB_EDITOR: Job RDDHANAD is invalid. Reason:
14.08.2023    09:17:56    <host_SID_Nr>    BTC    092    000    DDIC    @SR\Qinformation@    EFT    > Step 1 contains illegal values

SUM

TRBAT, WARNING:       Background job RDDIMPDP could not be started or terminated abnormally., HANA_DEPLOY_UPG , KBA , BC-UPG-TLS-TLA , Upgrade tools for ABAP , BC-ABA-SC , Dynpro and CUA engine , Problem