-1436 : ORA-01436: CONNECT BY loop in user data

Hi,

The following query throws connect by loop in user data:

SELECT sys_connect_by_path(jt.terr_id,'/')

    FROM jtf_terr_all jt,jtf_terr_usgs_all jtu

    WHERE jtu.source_id=-1600

    AND jtu.terr_id=jt.terr_id

    AND jt.terr_id<>1

    AND   jt.end_date_active >= sysdate

     AND   jt.start_date_active <= sysdate

    CONNECT BY PRIOR  jt.terr_id = jt.parent_territory_id ;   

Its been observed that query throw error at 2501 row.

I have tried to find out the cyclic loop records by using the following query:

SELECT sys_connect_by_path(jt.terr_id,'/')