In this case the removeTargetGroup parameter turns out to be NULL:

<h:dataTable value="#{project.targetGroups}"var="targetGroup">
 <h:column>
 <s:button value="#{targetGroup.name}" action="#{projectManager.removeTargetGroup(targetGroup)}"/>
 </h:column>
 </h:dataTable>

But in this case it is as it should be:

<h:dataTable value="#{project.targetGroups}"var="targetGroup">
 <h:column>
 <s:button value="#{targetGroup.name}" action="#{projectManager.removeTargetGroup(project.targetGroups[0])}"/>
 </h:column>
 </h:dataTable>

In both cases - targetGroup.name displays as it should.

How can it be that the action method parameter is NULL in the first case? Is it a configuration issue?

regards,

Peter