Trying to serialize nested subclasses of a nested class cause errors like this:

java.io.StreamCorruptedException: Unexpected byte found when reading an object: 50
at org.jboss.marshalling.river.RiverUnmarshaller.doReadObject(RiverUnmarshaller.java:708)
at org.jboss.marshalling.river.RiverUnmarshaller.doReadObject(RiverUnmarshaller.java:207)
at org.jboss.marshalling.river.RiverUnmarshaller.readFields(RiverUnmarshaller.java:1637)
at org.jboss.marshalling.river.RiverUnmarshaller.doInitSerializable(RiverUnmarshaller.java:1553)
at org.jboss.marshalling.river.RiverUnmarshaller.doInitSerializable(RiverUnmarshaller.java:1517)
at org.jboss.marshalling.river.RiverUnmarshaller.doReadNewObject(RiverUnmarshaller.java:1202)
at org.jboss.marshalling.river.RiverUnmarshaller.doReadObject(RiverUnmarshaller.java:270)
at org.jboss.marshalling.river.RiverUnmarshaller.doReadObject(RiverUnmarshaller.java:207)
at org.jboss.marshalling.AbstractUnmarshaller.readObject(AbstractUnmarshaller.java:85)
at org.infinispan.marshall.LowerLevelMarshall534545Test.test001(LowerLevelMarshall534545Test.java:108)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.testng.internal.MethodHelper.invokeMethod(MethodHelper.java:644)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:546)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:700)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1002)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:137)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:121)
at org.testng.TestRunner.runWorkers(TestRunner.java:908)
at org.testng.TestRunner.privateRun(TestRunner.java:617)
at org.testng.TestRunner.run(TestRunner.java:498)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:329)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:324)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:296)
at org.testng.SuiteRunner.run(SuiteRunner.java:201)
at org.testng.TestNG.createAndRunSuiteRunners(TestNG.java:915)
at org.testng.TestNG.runSuitesLocally(TestNG.java:879)
at org.testng.TestNG.run(TestNG.java:787)
at org.testng.remote.RemoteTestNG.run(RemoteTestNG.java:75)
at org.testng.RemoteTestNGStarter.main(RemoteTestNGStarter.java:79)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:110)
Caused by: an exception which occurred:
in field id
in object of type org.infinispan.marshall.LowerLevelMarshall534545Test$Child2

The issue, as correctly identified by Mihir Patel, is that when reading such Child2, RiverUnmarshaller detects parent to be incomplete and hence it does not read parent's attributes. This is a problem because on the marshalling side, parent's attributes are written before Child2's, hence the mismatch between the write and reading phase.