activiti_安装所需插件

activiti bpmn插件安装失败, 报错原因: Cannot complete the install because one or more required items could not be found. Software being installed: Activiti Eclipse BPMN 2.0 Designer 5.18.0.201508100929 (org.activiti.designer.feature.feature.group 5.18.0.201508100929) Missing requirement: Activiti Eclipse BPMN