Enterprise Manager is not able to connect to the database instance

Solution :

check the sysman and dbsnmp account status, If expired, please activate
SQL> select username,account_status from dba_users where username =’SYSMAN’;

USERNAME ACCOUNT_STATUS
—————————— ——————————–
SYSMAN EXPIRED

SQL> select username,account_status from dba_users where username =’DBSNMP’;

USERNAME ACCOUNT_STATUS
—————————— ——————————–
DBSNMP OPEN

So sysman account has been expired.  Please activate with old password and also Please check if this account has been locked, please unlock this account.

SQL> alter user sysman identified by Admin123;

User altered.

SQL> select user,account_status from dba_users where username=’SYSMAN’;

USER ACCOUNT_STATUS
—————————— ——————————–
SYS LOCKED(TIMED)

SQL> alter user sysman account unlock;

User altered.

It will work after start the dbconsole