Description of problem:
It is impossible to assign tasks created in task list when BPMS deployed on IBM Web Sphere.

There is a misconfiguration in jboss-bpms-6.0.2.GA-redhat-5-deployable-was8/business-central/WEB-INF/beans.xml
which contains:
<alternatives><class>org.jbpm.kie.services.cdi.producer.DefaultUserGroupInfoProducer</class></alternatives>

In previous version (6.0.2 ER1), where it worked correctly the beans.xml contained:
<alternatives>
<class>org.jbpm.kie.services.cdi.producer.JAASUserGroupInfoProducer</class>
</alternatives>

How reproducible:
Always

Steps to Reproduce:
1. Deploy BPMS distribution for WAS on WAS
2. Login with some user, go to task list and try creating new task

Actual results:
Task is not created and you get modal with message akin to "user of group 'null' does not exist"

Expected results:
It should be possible to create a task without errors.

Additional info:
This seems like some mistake in the productization process, because 6.0.x community sources contain correct configuration: https://github.com/droolsjbpm/kie-wb-distributions/blob/6.0.x/kie-wb/kie-wb-distribution-wars/src/main/was8/WEB-INF/beans.xml