Default username password for OEM is ,
username – sysman
password – whatever you set while installation (or)
Modify the password from the OEM repository and also specify both characters and numbers in the password string and if not it may stop you from logging in throwing ,
“[#EM_SYSTEM_POOL#:BadSQLEvaluation] ERROR dbjava.sqleval doWork.148 – Exception from BadSQLEvaluation: java.sql.SQLException: ORA-01017: invalid username/password; logon denied”
SQL> alter user sysman identified by "password123" account unlock; User altered.