Hi,
I forgot that you use jbpm-installer. The steps from above would work to setup manually your human task service as web archive (.war) in application server.
However jbpm-installer tries to simplify configuration of jbpm applications in .war files. So try these steps - open the file jbpm-installer/conf/default.jbpm.console.properties
and change
jbpm.console.task.service.host=127.0.0.1
to
jbpm.console.task.service.host=localhost
If it won't work, make sure that your human task service is listening on localhost on port 5153.