Oracle 12c – Table Redefinition Ends with ORA-02448

I'm trying to redefine a table to be partitioned.

What I did:

CREATE TABLE WERTEVAR_TMP(
    "WVTEIL" NUMBER(10,0),
    "WVMERKMAL" NUMBER(5,0),
    "WVUNTERS" NUMBER(5,0),
    "WVWERTNR" NUMBER(10,0),
    "WVWERT" FLOAT(126),
    "WVATTRIBUT" NUMBER(5,0),
    "WVPRUEFER" NUMBER(10,0),
    "WVPRUEFMIT" NUMBER(10,0),
    "WVMASCHINE" NUMBER(10,0),
    "WVNEST" NUMBER(10,0),
    "WVDATZEIT" DATE,
    "WVSTIANF" NUMBER(3,0),
    "WVCHARGE" VARCHAR2(20 BYTE),
    "WVAUFTRAG" VARCHAR2(20 BYTE),
    "WV0005" VARCHAR2(35 BYTE),
    "WV0009" VARCHAR2(255 BYTE),
    "WV0011" VARCHAR2(250 BYTE),
    "WV0014" VARCHAR2(40 BYTE),
    "WV0015" NUMBER(10,0),
    "WV0016" VARCHAR2(32 BYTE),
    "WV0017" VARCHAR2(32 BYTE),
    "WV0031" RAW(16),
    "MONITORING_VERSION" NUMBER DEFAULT 0,
    "WV0034" NUMBER(10,0),
    "WV0054" VARCHAR2(32 BYTE),
    "WV0055" VARCHAR2(32 BYTE),
    "WV0056" VARCHAR2(32 BYTE),
    "WV0057" VARCHAR2(32 BYTE),
    "WV0058" VARCHAR2(32 BYTE),
    "WV0059" VARCHAR2(32 BYTE),
    "WV0060" VARCHAR2(32 BYTE),
    "WV0061" NUMBER(10,0),
    "WV0062" NUMBER(10,0),
    "WV0063" NUMBER(10,0),
    "WV0080" VARCHAR2(64 BYTE),
    "WV0081" NUMBER(5,0)
)
STORAGE (INITIAL 65K NEXT 65K)
PARTITION BY RANGE (WVDATZEIT) INTERVAL (NUMTODSINTERVAL(1, 'day'))
SUBPARTITION BY HASH (WVMASCHINE) SUBPARTITIONS 8
(
    PARTITION P_BEFORE_2000 VALUES LESS THAN (TO_DATE('01-01-2000', 'DD-MM-YYYY'))
);

BEGIN
    DBMS_REDEFINITION.start_redef_table(
        uname         => 'CHYSTAT_STAGING_MONITORING',
        orig_table    => 'WERTEVAR',
        int_table     => 'WERTEVAR_TMP',
        options_flag  => DBMS_REDEFINITION.CONS_USE_ROWID
    );
END;

SET SERVEROUTPUT ON;
DECLARE
    l_errors  NUMBER;
BEGIN
    DBMS_REDEFINITION.copy_table_dependents(
        uname            => 'CHYSTAT_STAGING_MONITORING',
        orig_table       => 'WERTEVAR',
        int_table        => 'WERTEVAR_TMP',
        copy_indexes     => DBMS_REDEFINITION.CONS_ORIG_PARAMS,
        copy_triggers    => TRUE,
        copy_constraints => TRUE,
        copy_privileges  => TRUE,
        ignore_errors    => FALSE,
        num_errors       => l_errors,
        copy_statistics  => FALSE,
        copy_mvlog       => FALSE
    );

    DBMS_OUTPUT.put_line('Errors=' || l_errors);
END;

-- Complete the redefinition process
BEGIN
    DBMS_REDEFINITION.finish_redef_table(
    uname      => 'CHYSTAT_STAGING_MONITORING',
    orig_table => 'WERTEVAR',
    int_table  => 'WERTEVAR_TMP');
END;

But DBMS_REDEFINITION.finish_redef_table ends with:

Error report:
ORA-02448: constraint does not exist
ORA-06512: at "SYS.DBMS_REDEFINITION", line 105
ORA-06512: at "SYS.DBMS_REDEFINITION", line 3520
ORA-06512: at line 2
02448. 00000 -  "constraint does not exist"
*Cause:    The named constraint does not exist
*Action:   Stop trying to do something with a nonexistant constraint

I would appreciate any hint.