JXTA 2.7严重：World Peer Group无法实例化。

Question

尝试运行JXSE 2.7的示例文件//连接OSGI，Edge_Dimitri发送消息等，我收到此错误

PSE Membmership Service started.
Oct 23, 2012 8:20:13 AM net.jxta.impl.peergroup.StdPeerGroup initFirst
SEVERE: Failed to make PSE membership credential 'ready for join'
Oct 23, 2012 8:20:13 AM net.jxta.peergroup.WorldPeerGroupFactory newWorldPeerGroup
SEVERE: World Peer Group could not be instantiated.

net.jxta.exception.PeerGroupException: Failed to login to this group: null. Error=0
at net.jxta.impl.peergroup.StdPeerGroup.initFirst(StdPeerGroup.java:704)
at net.jxta.impl.peergroup.Platform.initFirst(Platform.java:214)
at net.jxta.impl.peergroup.GenericPeerGroup.init(GenericPeerGroup.java:907)
at net.jxta.peergroup.WorldPeerGroupFactory.newWorldPeerGroup(WorldPeerGroupFactory.java:312)
at net.jxta.peergroup.WorldPeerGroupFactory.<init>(WorldPeerGroupFactory.java:182)
at net.jxta.peergroup.NetPeerGroupFactory.<init>(NetPeerGroupFactory.java:203)
at net.jxta.platform.NetworkManager.startNetwork(NetworkManager.java:408)
at Examples.A_JXTA_Connection_And_Local_Configuration._160_Connecting_With_OSGi.main(_160_Connecting_With_OSGi.java:66)

这是我的Java Build路径（使用eclipse）

非常感谢任何帮助。感谢