We're trying to build an spi to extend the database model, and have been having issues, so I thought I'd try the domain-extension example that we based our spi on, just to make sure it's our code that's the problem, and it seems that it's not. Unless we're doing something else wrong! :) I cloned the source code and checked out the 3.2.1.Final tag, and built the whole project, to get the examples built. (I tried to 'mvn clean install' the examples folder in the distribution but it fails because it can't find the parent projects). I've just downloaded and extracted 3.2.1.Final distribution, I then copied the `domain-extension-example.jar` from the source code to the `<distribution>\standalone\deployments` folder and then ran `bin\standalone.bat`. It fails with the same issue that we are experiencing in our spi. I'm now struggling to work out why it's doing that, can anyone suggest what I'm doing wrong? Thanks! This is the log: 16:54:45,751 ERROR [org.jboss.msc.service.fail] (ServerService Thread Pool -- 58) MSC000001: Failed to start service jboss.undertow.deployment.default-server.default-host./auth: org.jboss.msc.service.StartException in service jboss.undertow.deployment.default-server.default-host./auth: java.lang.RuntimeException: RESTEASY003325: Failed to construct public org.keycloak.services.resources.KeycloakApplication(javax.servlet.ServletContext,org.jboss.resteasy.core.Dispatcher) at org.wildfly.extension.undertow.deployment.UndertowDeploymentService$1.run(UndertowDeploymentService.java:85) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) at org.jboss.threads.JBossThread.run(JBossThread.java:320) Caused by: java.lang.RuntimeException: RESTEASY003325: Failed to construct public org.keycloak.services.resources.KeycloakApplication(javax.servlet.ServletContext,org.jboss.resteasy.core.Dispatcher) at org.jboss.resteasy.core.ConstructorInjectorImpl.construct(ConstructorInjectorImpl.java:162) at org.jboss.resteasy.spi.ResteasyProviderFactory.createProviderInstance(ResteasyProviderFactory.java:2209) at org.jboss.resteasy.spi.ResteasyDeployment.createApplication(ResteasyDeployment.java:299) at org.jboss.resteasy.spi.ResteasyDeployment.start(ResteasyDeployment.java:240) at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.init(ServletContainerDispatcher.java:113) at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.init(HttpServletDispatcher.java:36) at io.undertow.servlet.core.LifecyleInterceptorInvocation.proceed(LifecyleInterceptorInvocation.java:117) at org.wildfly.extension.undertow.security.RunAsLifecycleInterceptor.init(RunAsLifecycleInterceptor.java:78) at io.undertow.servlet.core.LifecyleInterceptorInvocation.proceed(LifecyleInterceptorInvocation.java:103) at io.undertow.servlet.core.ManagedServlet$DefaultInstanceStrategy.start(ManagedServlet.java:231) at io.undertow.servlet.core.ManagedServlet.createServlet(ManagedServlet.java:132) at io.undertow.servlet.core.DeploymentManagerImpl.start(DeploymentManagerImpl.java:526) at org.wildfly.extension.undertow.deployment.UndertowDeploymentService.startContext(UndertowDeploymentService.java:101) at org.wildfly.extension.undertow.deployment.UndertowDeploymentService$1.run(UndertowDeploymentService.java:82) ... 6 more Caused by: javax.persistence.PersistenceException: [PersistenceUnit: keycloak-default] Unable to build Hibernate SessionFactory at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.persistenceException(EntityManagerFactoryBuilderImpl.java:954) at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:882) at org.keycloak.connections.jpa.util.JpaUtils.createEntityManagerFactory(JpaUtils.java:63) at org.keycloak.connections.jpa.DefaultJpaConnectionProviderFactory.lambda$lazyInit$0(DefaultJpaConnectionProviderFactory.java:201) at org.keycloak.models.utils.KeycloakModelUtils.suspendJtaTransaction(KeycloakModelUtils.java:544) at org.keycloak.connections.jpa.DefaultJpaConnectionProviderFactory.lazyInit(DefaultJpaConnectionProviderFactory.java:130) at org.keycloak.connections.jpa.DefaultJpaConnectionProviderFactory.create(DefaultJpaConnectionProviderFactory.java:78) at org.keycloak.connections.jpa.DefaultJpaConnectionProviderFactory.create(DefaultJpaConnectionProviderFactory.java:56) at org.keycloak.services.DefaultKeycloakSession.getProvider(DefaultKeycloakSession.java:163) at org.keycloak.models.jpa.JpaRealmProviderFactory.create(JpaRealmProviderFactory.java:51) at org.keycloak.models.jpa.JpaRealmProviderFactory.create(JpaRealmProviderFactory.java:33) at org.keycloak.services.DefaultKeycloakSession.getProvider(DefaultKeycloakSession.java:163) at org.keycloak.models.cache.infinispan.RealmCacheSession.getDelegate(RealmCacheSession.java:181) at org.keycloak.models.cache.infinispan.RealmCacheSession.getMigrationModel(RealmCacheSession.java:174) at org.keycloak.migration.MigrationModelManager.migrate(MigrationModelManager.java:70) at org.keycloak.services.resources.KeycloakApplication.migrateModel(KeycloakApplication.java:243) at org.keycloak.services.resources.KeycloakApplication.migrateAndBootstrap(KeycloakApplication.java:184) at org.keycloak.services.resources.KeycloakApplication$1.run(KeycloakApplication.java:143) at org.keycloak.models.utils.KeycloakModelUtils.runJobInTransaction(KeycloakModelUtils.java:227) at org.keycloak.services.resources.KeycloakApplication.<init>(KeycloakApplication.java:134) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at org.jboss.resteasy.core.ConstructorInjectorImpl.construct(ConstructorInjectorImpl.java:150) ... 19 more Caused by: org.hibernate.MappingException: Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:123) at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:77) at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:346) at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:444) at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:879) ... 42 more Caused by: org.hibernate.HibernateException: Unable to instantiate default tuplizer [org.hibernate.tuple.entity.PojoEntityTuplizer] at org.hibernate.tuple.entity.EntityTuplizerFactory.constructTuplizer(EntityTuplizerFactory.java:91) at org.hibernate.tuple.entity.EntityTuplizerFactory.constructDefaultTuplizer(EntityTuplizerFactory.java:116) at org.hibernate.tuple.entity.EntityMetamodel.<init>(EntityMetamodel.java:388) at org.hibernate.persister.entity.AbstractEntityPersister.<init>(AbstractEntityPersister.java:509) at org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:124) at sun.reflect.GeneratedConstructorAccessor98.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:96) ... 46 more Caused by: java.lang.reflect.InvocationTargetException at sun.reflect.GeneratedConstructorAccessor99.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at org.hibernate.tuple.entity.EntityTuplizerFactory.constructTuplizer(EntityTuplizerFactory.java:88) ... 54 more Caused by: java.lang.RuntimeException: by java.lang.NoClassDefFoundError: org/hibernate/proxy/HibernateProxy at javassist.util.proxy.ProxyFactory.createClass3(ProxyFactory.java:515) at javassist.util.proxy.ProxyFactory.createClass2(ProxyFactory.java:492) at javassist.util.proxy.ProxyFactory.createClass1(ProxyFactory.java:428) at javassist.util.proxy.ProxyFactory.createClass(ProxyFactory.java:400) at org.hibernate.proxy.pojo.javassist.JavassistProxyFactory.postInstantiate(JavassistProxyFactory.java:72) at org.hibernate.tuple.entity.PojoEntityTuplizer.buildProxyFactory(PojoEntityTuplizer.java:177) at org.hibernate.tuple.entity.AbstractEntityTuplizer.<init>(AbstractEntityTuplizer.java:157) at org.hibernate.tuple.entity.PojoEntityTuplizer.<init>(PojoEntityTuplizer.java:63) ... 58 more Caused by: javassist.CannotCompileException: by java.lang.NoClassDefFoundError: org/hibernate/proxy/HibernateProxy at javassist.util.proxy.FactoryHelper.toClass(FactoryHelper.java:170) at javassist.util.proxy.ProxyFactory.createClass3(ProxyFactory.java:507) ... 65 more Caused by: java.lang.NoClassDefFoundError: org/hibernate/proxy/HibernateProxy at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:763) at sun.reflect.GeneratedMethodAccessor314.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at javassist.util.proxy.FactoryHelper.toClass2(FactoryHelper.java:182) at javassist.util.proxy.FactoryHelper.toClass(FactoryHelper.java:164) ... 66 more Caused by: java.lang.ClassNotFoundException: org.hibernate.proxy.HibernateProxy from [Module "deployment.domain-extension-example.jar:main" from Service Module Loader] at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:198) at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:363) at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:351) at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:93) ... 73 more