derby创建索引时的问题

[宋迪@]

derby创建索引之后在SYS.SYSCONGLOMERATES这张表里DESCRIPTOR列会产生以下异常信息：
<failed to load>
java.sql.SQLException: 编组或解组用户定义的类型时出错：org.apache.derby.catalog.types.IndexDescriptorImpl
at org.apache.derby.client.am.SQLExceptionFactory40.getSQLException(Unknown Source)
at org.apache.derby.client.am.SqlException.getSQLException(Unknown Source)
at org.apache.derby.client.am.ResultSet.getObject(Unknown Source)
at com.intellij.persistence.jdbc.impl.RemoteResultSetImpl.getCurrentRow(RemoteResultSetImpl.java:1235)
at com.intellij.persistence.jdbc.impl.RemoteResultSetImpl.getObjects(RemoteResultSetImpl.java:1192)
at sun.reflect.GeneratedMethodAccessor31.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:322)
at sun.rmi.transport.Transport$1.run(Transport.java:177)
at sun.rmi.transport.Transport$1.run(Transport.java:174)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:173)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:553)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:808)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:667)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:724)
Caused by: org.apache.derby.client.am.SqlException: 编组或解组用户定义的类型时出错：org.apache.derby.catalog.types.IndexDescriptorImpl
at org.apache.derby.client.am.Cursor.get_UDT(Unknown Source)
at org.apache.derby.client.am.Cursor.getObject(Unknown Source)
at org.apache.derby.client.am.ResultSet.getObjectX(Unknown Source)
... 17 more
Caused by: java.lang.ClassNotFoundException: org.apache.derby.catalog.types.IndexDescriptorImpl
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:270)
at java.io.ObjectInputStream.resolveClass(ObjectInputStream.java:623)
at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1610)
at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1515)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1769)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)
... 20 more
, false, 'a30931b5-0141-e303-871b-000000c74420');

请问各位大师这是什么原因造成的。