ORA-20603: Updating timezone region of a target is not supported
Enterprise manager does not start after updating the database. The emdb.nohup has an ORA-20603: Updating timezone region of a target is not supported error message in it.
The problemThe timezones have been updated within the database.
SolutionAs Oracle run:
$ORACLE_HOME/bin/emctl resetTZ agent
and follow the instructions. You'll need the sysman or sys password to make the changes.