ERROR: Agent Configuration Failed SEVERE:emctl secure agent command has failed with status=1

Error: 

This error occurs during OEM 12C Agent installation

ERROR: Agent Configuration Failed SEVERE:emctl secure agent command has failed with status=1

SEVERE: oracle.sysman.top.agent:Agent configuration has failed

or

ERROR: Agent Configuration Failed SEVERE: Agent port passed by user is busy and cannot proceed with the configuration. Pass a free port and retry the configuration.

Solution: 

If you get this error verify Agent password and port 3872 from OEM to Agent.