EMCTL(Enterprise Manager) Invalid Connection Pool. ERROR = ORA-28000:

Check SYSMAN and DBSNMP account status...this problem can be related with wrong password configuration of emctl...

first check status of SYSMAN and DBSNMP;

select account_status,lock_date,username from dba_users where username in ('SYSMAN','DBSNMP');

ACCOUNT_STATUS                   LOCK_DATE       USERNAME
-------------------------------- --------------- ------------------------------
OPEN                                                                          DBSNMP
LOCKED(TIMED)                         17-06-13              SYSMAN

SYSMAN status LOCKED ...before unlocking sysman accout stop the dbconsole;

 emctl stop dbconsole

Then

 sqlplus / as sysdba

SQL> alter user sysman account unlock;
SQL> alter user sysman identified by  NEWPASSWORD;

and set password of emctl  with oracle user; and set dbconsole password as NEWPASSWORD

emctl setpasswd dbconsole

start dbconsole

emctl start dbconsole 

-Erol