ORA-31403: change table already contains a column

Hi,

Could you please help me to resolve this


SQL> begin
  2  DBMS_CDC_PUBLISH.ALTER_CHANGE_TABLE (OWNER =>'TESTCDCPUB',
  3  CHANGE_TABLE_NAME =>'TEST_HOLD_REASON_CT',
  4  OPERATION =>'ADD',
  5  COLUMN_LIST =>'CDC_FLAG VARCHAR2(50)',
  6  RS_ID =>'N',
  7  ROW_ID =>'N',
  8  USER_ID =>'N',
  9  TIMESTAMP =>'Y',
 10  OBJECT_ID =>'N',
 11  SOURCE_COLMAP =>'N',
 12  TARGET_COLMAP =>'N');
 13  end;
 14  /
begin
*
ERROR at line 1:
ORA-31403: change table  already contains a column
ORA-06512: at "SYS.DBMS_CDC_PUBLISH", line 633
ORA-06512: at line 2