Not a valid month error

I am trying to use the following insert statement but getting an error:"ORA-01843: not a valid month"

What is the problem , I have converted the sysdate using this before with out any errors?

Thank you in advance
Lance

insert into cp_license_use(Select A.Pc_session_id, a.pc_session_user_name, To_Char(SYSDATE,'MM/DD/YYYY HH:MI') From pt_client_event A where A.pc_event_op = 'LAUNCH' and A.pc_date >=SYSDATE -1 minus
Select B.Pc_session_id, b.pc_session_user_name, To_Char(SYSDATE,'MM/DD/YYYY HH:MI') From pt_client_event B where B.Pc_event_op = 'LOGOUT' and B.pc_date
>=SYSDATE -1);

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Lance Prais
  INET: lprais_at_ts.checkpoint.com

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