Shiro Ehcache 报错?报错

670300 [shiro-active%0053ession%0043ache.data] ERROR net.sf.ehcache.store.disk.DiskStorageFactory - Disk Write of 7c264daa-d12e-457a-b6a1-ce76f4275f6b failed: 
net.sf.ehcache.CacheException: Failed to serialize element due to ConcurrentModificationException. This is frequently the result of inappropriately sharing thread unsafe object (eg. ArrayList, HashMap, etc) between threads
at net.sf.ehcache.store.disk.DiskStorageFactory.serializeElement(DiskStorageFactory.java:401)
at net.sf.ehcache.store.disk.DiskStorageFactory.write(DiskStorageFactory.java:381)
at net.sf.ehcache.store.disk.DiskStorageFactory$DiskWriteTask.call(DiskStorageFactory.java:473)
at net.sf.ehcache.store.disk.DiskStorageFactory$PersistentDiskWriteTask.call(DiskStorageFactory.java:1067)
at net.sf.ehcache.store.disk.DiskStorageFactory$PersistentDiskWriteTask.call(DiskStorageFactory.java:1051)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(Unknown Source)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
at java.util.HashMap$EntryIterator.next(Unknown Source)
at java.util.HashMap$EntryIterator.next(Unknown Source)
at java.util.HashMap.writeObject(Unknown Source)
at sun.reflect.GeneratedMethodAccessor23.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at java.io.ObjectStreamClass.invokeWriteObject(Unknown Source)
at java.io.ObjectOutputStream.writeSerialData(Unknown Source)
at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source)
at java.io.ObjectOutputStream.writeObject0(Unknown Source)
at java.io.ObjectOutputStream.writeObject(Unknown Source)
at org.apache.shiro.session.mgt.SimpleSession.writeObject(SimpleSession.java:461)
at sun.reflect.GeneratedMethodAccessor27.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at java.io.ObjectStreamClass.invokeWriteObject(Unknown Source)
at java.io.ObjectOutputStream.writeSerialData(Unknown Source)
at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source)
at java.io.ObjectOutputStream.writeObject0(Unknown Source)
at java.io.ObjectOutputStream.defaultWriteFields(Unknown Source)
at java.io.ObjectOutputStream.defaultWriteObject(Unknown Source)
at net.sf.ehcache.Element.writeObject(Element.java:867)
at sun.reflect.GeneratedMethodAccessor26.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at java.io.ObjectStreamClass.invokeWriteObject(Unknown Source)
at java.io.ObjectOutputStream.writeSerialData(Unknown Source)
at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source)
at java.io.ObjectOutputStream.writeObject0(Unknown Source)
at java.io.ObjectOutputStream.writeObject(Unknown Source)
at net.sf.ehcache.util.MemoryEfficientByteArrayOutputStream.serialize(MemoryEfficientByteArrayOutputStream.java:97)
at net.sf.ehcache.store.disk.DiskStorageFactory.serializeElement(DiskStorageFactory.java:399)
... 10 more