SQL & PL/SQL

Hi,

I had an error message ORA-02287: sequence number not allowed here when running sql insert statement below.

INSERT INTO SI_KEY_DBF
(M_IDENTITY, M_REF, M_GROUP, M_STATUS, M_TYPE, M_MULTIPLE, M_START, M_END, M_PREVIOUS, M_NEXT, M_INS_DATE, M_MOD_DATE,
M_INS_TIME, M_MOD_TIME, M_AMEND, M_LABEL, M_ENTITY, M_TRN_FAMILY, M_TRN_GROUP, M_TRN_TYPE, M_CURRENCY,
M_O_CUR, M_NOVO, M_CRDE, M_CODE, M_USER, M_VAL_STATUS, M_STL_METHOD, M_TRD_SECT, M_COMMENT, M_MARKET,
M_CLEARER, M_SI_TCI)
(SELECT M_IDENTITY, (SELECT SI_KEY_DBFS.nextval FROM dual), M_GROUP, M_STATUS, M_TYPE, M_MULTIPLE, NULL, NULL, M_PREVIOUS, M_NEXT, SYSDATE, SYSDATE,
To_Char(SYSDATE,'HH:MM:SS'), To_Char(SYSDATE,'HH:MM:SS'), 0, M_LABEL, M_ENTITY, M_TRN_FAMILY,
M_TRN_GROUP, M_TRN_TYPE, M_CURRENCY, M_O_CUR, M_NOVO, M_CRDE, M_CODE, M_USER, M_VAL_STATUS,
M_STL_METHOD, M_TRD_SECT, M_COMMENT, M_MARKET, M_CLEARER, M_SI_TCI FROM SI_KEY_DBF WHERE M_REF IN
(SELECT M_REF FROM TABLE#DATA#SITRN_DBF WHERE M_HLD_AC IN (SELECT IDXOAC FROM DDINDX)))

Can anyone help me on how to solve this problem? Really appreciate your help. Thanks.