1952422 - ERROR: data conversion failed. rc = 2 during new system installation or system copy (export/import)

New system installation or R3load based system copy (inc. unicode migration) fail in ABAP export or in ABAP import phase using Software Provisioning Manager (SAP Note: 1680045).
The name of the failed package(s) is listed in export/import_monitor.java.log and also in export/import_monitor.log. These files and package-logs are in the path of the used sapinst_instdir, (/<sapinst_instdir>/<SAPTABART>.log).

The failed package-logs contain the error entry: "ERROR: data conversion failed. rc = 2" but additional error texts depend on the root cause:

1.

e.g. DOKCLU.log:

...
myCluster (127.25.Imp): 706: error when retrieving field description for physical table DOKCLU.
myCluster (127.25.Imp): 709: return code received from nametab is 32
myCluster (127.25.Imp): 297: error when retrieving physical nametab for table DOKCLU.
(CNV) ERROR: data conversion failed. rc = 2
...
Further cluster tables may be affected as well.

2.

...
myCluster (127.23.Imp): 3635: page zero missing; page 1 encountered inst
ead.
myCluster: <cluster table name> **500****SETS **01012050K_2050
****0000351892**
myCluster (127.23.Imp): 2919: failed to convert transparent fields of
cluster item.
myCluster (127.23.Imp): 324: error during conversion of cluster item.
myCluster (127.23.Imp): 327: affected physical table is <cluster table name>.
(CNV) ERROR: data conversion failed. rc = 2
...
Further cluster tables may be affected as well.

3.

...
Error -21 during CsInitDecompr
PROGNAME 00 53 00 41 00 50 00 4c 00 43 00 4b 00 41 00 50 |. . . . . . . . |
PROGNAME 00 50 00 30 00 31 00 50 00 45 00 52 00 53 00 20 |. . . . . . . . |
PROGNAME 00 20 00 20 00 20 00 20 00 20 00 20 00 20 00 20 |. . . . . . . . |
PROGNAME 00 20 00 20 00 20 00 20 00 20 00 20 00 20 00 20 |. . . . . . . . |
PROGNAME 00 20 00 20 00 20 00 20 00 20 00 20 00 20 00 20 |. . . . . . . . |
DYNPNUMBER 00 32 00 30 00 30 00 30 |.2.0.0.0 |
R3STATE 00 41 |.A |
(CNV) ERROR: data conversion failed. rc = 2
...
- during the export of DYNPSOURCE table -

SAP system installation based on SAP NetWeaver Releases lower than 7.40 with Oracle DB (like Oracle 19) using Kernel 7.21_EXT or 7.22_EXT
R3load based system copy - or unicode migration - of AS ABAP or of AS ABAP+Java system based on SAP NetWeaver 7.00 and higher

SWPM R3load Unicode Migration CU&UC unicode conversion AABLG REGUC SFHOA DOKCLU T512CLU RFBLG KOCL , KBA , BC-INS-MIG , OS/DB Migrations with SWPM and DB refresh , BC-I18-UNI , Unicode , Problem