WAS Admin already checked the password, there is no special char in it. Other operations under the same Mbean (ListenerManagement) can be invoked such as ListenerStatus, only certain operation, such as Start, Stop, fail to be invoked with the attached error message.
I have read the IBM article as you suggested, however, the property file (<DC_HOME>/runtime/<server>/datacollector.properties) IBM mentioned in the article does not exist in our Linux server. We use WAS 8.5/Red Head Linux 2.6. The same program is working fine in our WAS 8.0/AIX 7.1 env.