The Agent does not start because of incorrect time zone.
- check ORACLE_HOME/sysman/admin/supportedtzs.lst and ORACLE_HOME/sysman/admin/nsupportedtzs.lst for a correct value on TZ
- Comment the line AgentTZRegion="<some value>" in
ORACLE_HOME/<hostname>_<SID>/sysman/config/emd.properties - export TZ=<chosen time zone from step 1>
- emctl config agent getTZ
- emctl config agent updateTZ
- emctl start dbconsole
Note: on 11.1 and higher DB Console, it is enough to run "emctl resettz agent" and then follow the instructions in the output (ie. running th mgmt_target.set_agent_tzrgn procedure) to change or set the correct timezone on the DB Console.