title: Getting "java.io.IOException: Unsupported protocol version 22" while using the shared file store in Infinispan
body: <p>I'm getting the following exception while using file store based cache store which is shared among multiple nodes.</p>
  
  <pre><code>Caused by: org.infinispan.commons.CacheException: Unable to start cache loaders
      at org.infinispan.persistence.manager.PersistenceManagerImpl.start(PersistenceManagerImpl.java:174)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:498)
      at org.infinispan.commons.util.ReflectionUtil.invokeAccessibly(ReflectionUtil.java:168)
      ... 73 more
  Caused by: org.infinispan.persistence.spi.PersistenceException: java.io.IOException: Unsupported protocol version 22
      at org.infinispan.persistence.file.SingleFileStore.start(SingleFileStore.java:135)
      at org.infinispan.persistence.manager.PersistenceManagerImpl.start(PersistenceManagerImpl.java:141)
      ... 78 more
  Caused by: java.io.IOException: Unsupported protocol version 22
      at org.jboss.marshalling.river.RiverUnmarshaller.start(RiverUnmarshaller.java:1249)
      at org.infinispan.commons.marshall.jboss.AbstractJBossMarshaller.startObjectInput(AbstractJBossMarshaller.java:128)
      at org.infinispan.marshall.core.VersionAwareMarshaller.startObjectInput(VersionAwareMarshaller.java:142)
      at org.infinispan.marshall.core.VersionAwareMarshaller.objectFromByteBuffer(VersionAwareMarshaller.java:98)
      at org.infinispan.commons.marshall.AbstractDelegatingMarshaller.objectFromByteBuffer(AbstractDelegatingMarshaller.java:80)
      at org.infinispan.persistence.file.SingleFileStore.rebuildIndex(SingleFileStore.java:212)
      at org.infinispan.persistence.file.SingleFileStore.start(SingleFileStore.java:126)
      ... 79 more
  </code></pre>
  
  <p>This is how my cache config looks like:</p>
  
  <pre><code>&lt;distributed-cache name="singletons"&gt;
          &lt;versioning scheme="SIMPLE"/&gt;
              &lt;persistence passivation="false" &gt;
                  &lt;file-store
                      path="${infinispan.dir}/broker-ds/singletons"
                      fetch-state="true" shared="true" preload="true" /&gt;
              &lt;/persistence&gt;
          &lt;/distributed-cache&gt;
  </code></pre>
  
  <p>Any clues on what is going wrong? I'm using Infinispan 8.1 version.</p>
  
  <p>Update:</p>
  
  <p>Instead of shared file based store, I've used JDBC based shared store and things worked fine. </p>