The sysman password expires and the oem cannot use it.

09:29:47, 309 [HTTPThreadGroup-5] ERROR eml. OMSHandshake processFailure.808-OMSHandshake failed. (agent url = https: // szpms1: 1830/emd/main) (ERROR = INTERNAL_ERROR) (CAUSE = java. SQL. SQLException: ORA-28000: the account is locked
09:29:47, 856 [HTTPThreadGroup-5] ERROR conn. ConnectionService verifyRepositoryEx.891-Invalid Connection Pool. ERROR = ORA-28000: the account is locked

OEM (Oracle Enterprise Manager) cannot work properly due to SYSMAN User Password Expiration
1. Stop OEM service on all nodes
Emctl stop dbconsole

Confirm status after stopping
Emctl status dbconsole

2. Go to the database and modify the sysman user password.
Alter user sysman identified by passw0rd;
Alter user sysman account unlock;

3. Go to each node to modify the configuration file emoms. properties.
Directory $ ORACLE_HOME/$ {HOSTNAME }_$ {ORACLE_UNQNAME}/sysman/config
Cd/oracle/11gr2/szpms1_szpmsdb/sysman/config
Cd/oracle/11gr2/szpms2_szpmsdb/sysman/config

Oracle. sysman. eml. mntr. emdRepPwd = c509e4dc8aa740d7 -- change the password to the new one.
Oracle. sysman. eml. mntr. emdRepPwdEncrypted = TRUE -- TRUE to FALSE

4. Restart the OEM service on all nodes
Emctl start dbconsole