When running a cache in distributed mode with but with just one instance running. NumOwners set to two or more.
Insert objects which do not implement the serializable interface.
Bring up a second cache instance and upon the join even the following exception is thrown

[java] 6585 [main] DEBUG org.infinispan.jmx.ResourceDMBean - @MBean description set - Component that handles distribution of content across a cluster
[java] 6587 [main] DEBUG org.infinispan.jmx.ResourceDMBean - @MBean description set - Manager that handles MVCC locks for entries
[java] 6588 [main] DEBUG org.infinispan.jmx.ResourceDMBean - @MBean description set - General statistics such as timings, hit/miss ratio, etc.
[java] 6590 [main] DEBUG org.infinispan.jmx.ResourceDMBean - @MBean description set - Manages all remote calls to remote cache instances in the cluster.
[java] 6594 [main] DEBUG org.infinispan.jmx.ResourceDMBean - @MBean description set - Component that manages the cache's participation in JTA transactions.
[java] 6595 [main] INFO org.infinispan.jmx.CacheJmxRegistration - MBeans were successfully registered to the platform mbean server.
[java] 6595 [Rehasher-redlappie-1032] DEBUG org.infinispan.distribution.JoinTask - Commencing
[java] 6597 [main] INFO org.infinispan.factories.ComponentRegistry - Infinispan version: Infinispan 'Starobrno' 4.0.0.BETA2
[java] 6742 [Rehasher-redlappie-1032] DEBUG org.infinispan.distribution.JoinTask - Retrieved old consistent hash address list [redlappie-23510]
[java] 6742 [Rehasher-redlappie-1032] DEBUG org.infinispan.distribution.JoinTask - Retrieved old consistent hash address list [redlappie-23510]
[java] 6766 [Rehasher-redlappie-1032] DEBUG org.infinispan.distribution.JoinTask - Retrieved old consistent hash address list [redlappie-23510]
[java] 8421 [Rehasher-redlappie-1032] INFO org.infinispan.distribution.JoinTask - Completed in 2.04 seconds!
[java] 8533 [Rehasher-redlappie-1032] INFO org.infinispan.distribution.JoinTask - Completed in 1.94 seconds!
[java] 9640 [Rehasher-redlappie-1032] ERROR org.infinispan.remoting.rpc.RpcManagerImpl - unexpected error while replicating
[java] java.lang.ClassCastException: java.io.NotSerializableException cannot be cast to org.infinispan.remoting.responses.Response
[java] at org.infinispan.remoting.transport.jgroups.JGroupsTransport.invokeRemotely(JGroupsTransport.java:378)
[java] at org.infinispan.remoting.rpc.RpcManagerImpl.invokeRemotely(RpcManagerImpl.java:87)
[java] at org.infinispan.remoting.rpc.RpcManagerImpl.invokeRemotely(RpcManagerImpl.java:106)
[java] at org.infinispan.distribution.JoinTask.performRehash(JoinTask.java:118)
[java] at org.infinispan.distribution.RehashTask.call(RehashTask.java:52)
[java] at org.infinispan.distribution.RehashTask.call(RehashTask.java:30)
[java] at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
[java] at java.util.concurrent.FutureTask.run(FutureTask.java:138)
[java] at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
[java] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
[java] at java.lang.Thread.run(Thread.java:619)
[java] 9641 [Rehasher-redlappie-1032] ERROR org.infinispan.distribution.JoinTask - Caught exception!
[java] org.infinispan.CacheException: java.lang.ClassCastException: java.io.NotSerializableException cannot be cast to org.infinispan.remoting.responses.Response
[java] at org.infinispan.remoting.rpc.RpcManagerImpl.invokeRemotely(RpcManagerImpl.java:100)
[java] at org.infinispan.remoting.rpc.RpcManagerImpl.invokeRemotely(RpcManagerImpl.java:106)
[java] at org.infinispan.distribution.JoinTask.performRehash(JoinTask.java:118)
[java] at org.infinispan.distribution.RehashTask.call(RehashTask.java:52)
[java] at org.infinispan.distribution.RehashTask.call(RehashTask.java:30)
[java] at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
[java] at java.util.concurrent.FutureTask.run(FutureTask.java:138)
[java] at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
[java] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
[java] at java.lang.Thread.run(Thread.java:619)
[java] Caused by: java.lang.ClassCastException: java.io.NotSerializableException cannot be cast to org.infinispan.remoting.responses.Response
[java] at org.infinispan.remoting.transport.jgroups.JGroupsTransport.invokeRemotely(JGroupsTransport.java:378)
[java] at org.infinispan.remoting.rpc.RpcManagerImpl.invokeRemotely(RpcManagerImpl.java:87)
[java] ... 9 more