Target Manager failed at Startup: targets.xml was rejected: loaded with a wrong agent token

Trying to start the oracle management agent on client and it is failing to start and getting the error below:

$ ./emctl start agent
Oracle Enterprise Manager Cloud Control 12c Release 2
Copyright (c) 1996, 2012 Oracle Corporation.  All rights reserved.
Starting agent .............. failed.
Target Manager failed at Startup: targets.xml was rejected: loaded with a wrong agent token
Consult emctl.log and emagent.nohup in: /u01/agent12c/agent_inst/sysman/log



Solution :

Go to /u01/agent12c/agent_inst/sysman/emd and
mv targets.xml target.xml.backup

create new targets.xml with below content


<Targets>

</Targets>

Trying starting the agent with

emctl start agent

go back to your targets.xml file and cat it to get value of AGENT_TOKEN

$ cat targets.xml
<Targets AGENT_TOKEN="B7579B0E4405142405C6FCA2F86B2D2440FC93784BBA17229895F56E933ACA4F"/>
$

-- Stop agent

emctl stop agent

go to targets.xml.backup and modify the AGENT_TOKEN with current value.

remove  targets.xml which has got

<Targets AGENT_TOKEN="B7579B0E4405142405C6FCD2440FC93784BBA17229895F56E9334F"/>

Rename targets.xml.backup to targets.xml

start agent

Wallah it works !!!