ORA-01723 when GATHER_TABLE_STATS

 Hi folks,
I am doing a DBMS_STATS.GATHER_TABLE_STATS on a table and it returns immediately with the error ORA-01723: zero-length columns are not allowed. Here is the snippet:

SQL> exec DBMS_STATS.GATHER_TABLE_STATS('HUGO', 'MY_MESSAGE');
BEGIN DBMS_STATS.GATHER_TABLE_STATS('HUGO', 'MY_MESSAGE'); END;
*
ERROR at line 1:
ORA-01723: zero-length columns are not allowed
ORA-06512: at "SYS.DBMS_STATS", line 13437
ORA-06512: at "SYS.DBMS_STATS", line 13457
ORA-06512: at line 1

SQL> desc HUGO.MY_MESSAGE
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 NID                                       NOT NULL NUMBER(20)
 NART                                               CHAR(4)
 DATUM                                              DATE
 STATUS                                             VARCHAR2(3)
 PARTNER                                            VARCHAR2(5)
 SENDE_ANZ                                          NUMBER(5)