ORA-22950: cannot ORDER objects without MAP or ORDER method

Hello everybody,
I have a SQL Script that does some select form different tables.Below is my query:

set term off
/
    set heading off
/
    set linesize 400
/
    set feedback off
/
    spool C:\outfile.txt
/
SELECT
c.topic_key,
c.topic_label,
g.provider_document_id,
        g.document_text hw_doc_type,
count(i.user_id) hits,
i.session_id,
i.update_date
FROM
topic c,
topic_type_ref d,
        topic_type e,
document g,
document_ref f,
ehealth_audit i,
audit_parms h
WHERE
c.topic_key = d.topic_key
 AND
        d.topic_type_key = e.topic_type_key
 AND
        g.document_key = f.document_key
 AND
        h.name = 'topicKey'
 AND
        h.value = to_char(c.topic_key)
 AND
        g.provider_id = 'HW'
 AND
        h.audit_key = i.audit_key
 AND
(i.method_name = 'getTopicOverview' 
 OR 
        i.method_name = 'getTopicInDepth'
 OR
        i.method_name = 'getDocument')
 AND     
i.user_id is not null
 AND 
        i.session_id is not null
 AND
        hw_doc_type = 'nci'
 AND
        (i.update_date > to_date('10/01/2003','MM/DD/YYYY') 
 AND 
        i.update_date < to_date ('12/31/2003','MM/DD/YYYY')
 AND    
        c.topic_label = 'nci')
 AND
        g.document_text like '%HWDOCUMENT%'
 GROUP BY
        c.topic_key,
        c.topic_label,
g.provider_document_id,
        g.document_text,
i.session_id,
i.update_date
/
    spool off
/

When I execute this script: I get the following error:
SELECT
*
ERROR at line 1:
ORA-22950: cannot ORDER objects without MAP or ORDER method
Can somebody tell me what the error is?I assume it is related to the group by clause but not able to find the bug.This is very very urgent.Help wanted from Ranchers!
Thanks,
Prabha

1st, it is a big query, one way to debug queries to to take a little off, bit by bit till it runs, then you know the last thing you moved was a cause. Not necessarily the only problem though.
Another thing I noticed, and it depends on how you are running the lines, but I don't see a semi-colons, well you do have slashes, so that might be nothing.
Other than that the query looks good to me.

Mark

OK I just saw this.

ORA-22950: cannot order objects with without map or order method
Cause: Object types must have map or order methods defined for all comparisons other than equality and inequality comparisons.
Action: Define a map or order method for the object type.

What that says to me is that there is some kind of Object. Is the Object the document's text? because you use like which might be considered "NOT" an equality or inequality comparison.
Just a wild guess.
Mark