Sun Portal Server - Authentication Failed

A local university has Sun Java System Portal Server 7.1 deployed. We are the vendor that helped with the deployment and maintenance. 

We got a call few days back. The customer was not able to login to Portal Server Console (aka /psconsole). I asked for the error message and was told "Authentication Failed" (Please reenter username and password).

Well, I was thinking: "Come on, please reenter the correct username and password. What is more difficult than this?"

The customer told me very firmly that he did keyed in the correct username and password. 

Ok, let's look at the logs then. 

appuser@portal1 # tail -100f portal.admin.console.0.0.log

[#|2009-08-13T13:06:58.079+0800|SEVERE|SJS Portal Server|debug.com.sun.portal.admin.console|ThreadID=246; ClassName=com.sun.portal.admin.console.common.PSBaseBean; MethodName=log; |Failed to authenticate with JMX Server: LoginBean.login()

javax.management.remote.JMXProviderException: Connection refused

        at com.sun.cacao.agent.impl.AbstractCacaoConnectorProvider.newJMXConnector(AbstractCacaoConnectorProvider.java:403)

Oh, that's easy.

root@portal1 # cacaoadm status

default instance is ENABLED at system startup. 

default instance is not running. 

Hmm.. why is CACAO agent not running? 

root@portal1 # cacaoadm start

root@portal1 # cacaoadm status

default instance is ENABLED at system startup. 

Smf monitoring process: 

22058

22059

Uptime: 0 day(s), 0:0

The solution is to start the CACAO agent and log-in is fine after that. 

Well, I must admit the error message is not friendly though. Hard for debugging.