Oracle Database Discussions

Gurus,

I get following error message when I triy to execute this query :-

SQL> select distinct 'alter tablespace '||tab.tablespace_name||' begin backup;'
2 from dba_tablespaces tab, dba_data_files ddf, v$backup back
3 where tab.tablespace_name = ddf.tablespace_name and
ddf.file_id = back.file# and
4 5 tab.status = 'ONLINE' and
6 tab.contents != 'TEMPORARY' and
7 back.status != 'ACTIVE';
select distinct 'alter tablespace '||tab.tablespace_name||' begin backup;'
*
ERROR at line 1:
ORA-00235: controlfile fixed table inconsistent due to concurrent update

I have tried to execute this query for around 3-4 hours but always hit this error.

Can anyone advice how do I resolve this?