wrong version of java?

[adallolio]

2000-01-01 00:29:33.057:INFO:oejwc.WebSocketClient:main: Started org.eclipse.jetty.websocket.client.WebSocketClient@1d8d10a
[2000-01-01, 00:29:38] Listening for Announces on port 30101
Exception in thread "UDPTransport: Dispacher Thread 11567059" java.lang.NoClassDefFoundError: java/awt/datatransfer/Transferable
at pt.lsts.imc.IMCDefinition.createHeader(Unknown Source)
at pt.lsts.imc.IMCDefinition.nextMessage(Unknown Source)
at pt.lsts.imc.IMCDefinition.parseMessage(Unknown Source)
at pt.lsts.imc.net.UDPTransport$2.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: java.awt.datatransfer.Transferable
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 4 more