Cannot choose called element

[ttdactiviti]

I am using Eclipse 4.3.1 + Activiti Eclipse BPMN2.0 Designer 5.14.1,
The problem I encountered is, In Activiti Explorer View, I can't choose called element(of course it's existed) of Call activity.
Does anybody know this? Thanks in advance.
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[bdg]

Same problem here.  I am using Eclipse 4.4.1 + Activiti Eclipse BPMN2.0 Designer 5.15.0.

Please advise.  Thanks.