Hello there, I’m currently implementing a User Storage SPI in Scala using Akka which is the main protocol used within our back services. I first encountered some troubles regarding sbt assembly and the configuration files, leading to the creation of this ticket here on lightbend forum https://discuss.lightbend.com/t/configuration-error-when-deploying-akka-a... <https://discuss.lightbend.com/t/configuration-error-when-deploying-akka-a... I finally managed to retrieve correctly my configuration file adding it manually and reading it via ConfigFactory.parseFile(filename) However, now I’m facing a new exception : I get an ClassNotFoundException for the class akka.event.DefaultLoggingFilter at startup. A message with the same issue has already been published two years ago on the mailing list but doesn’t have any precise answer. Does anyone know what may be causing this error and how to solve it? Or maybe have a sample of working integration of a Scala User Storage SPI using Akka? Here is the complete stack trace I’m getting : 09:19:32,530 WARN [org.keycloak.services] (default task-466) KC-SERVICES0013: Failed authentication: java.lang.ClassNotFoundException: akka.event.DefaultLoggingFilter from [Module "deployment.keycloak-server.war" from Service Module Loader] at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:255) at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:410) at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:398) at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:116) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:348) at akka.actor.ReflectiveDynamicAccess.$anonfun$getClassFor$1(ReflectiveDynamicAccess.scala:22) at scala.util.Try$.apply(Try.scala:213) at akka.actor.ReflectiveDynamicAccess.getClassFor(ReflectiveDynamicAccess.scala:21) at akka.actor.ReflectiveDynamicAccess.createInstanceFor(ReflectiveDynamicAccess.scala:39) at akka.actor.ActorSystemImpl.<init>(ActorSystem.scala:780) at akka.actor.ActorSystem$.apply(ActorSystem.scala:246) at akka.actor.ActorSystem$.apply(ActorSystem.scala:289) at akka.actor.ActorSystem$.apply(ActorSystem.scala:264) at med.lib.service.client.MicroServiceClient.$init$(MicroServiceClient.scala:27) at med.lib.service.client.KeycloakDataServicesClient.<init>(KeycloakDataServicesClient.scala:18) at med.lib.service.keycloak.DSInterface.<init>(DSInterface.scala:22) at med.lib.service.keycloak.DSUserStorageProvider.<init>(DSUserStorageProvider.scala:19) at med.lib.service.keycloak.DSUserStorageProviderFactory.create(DSUserStorageProviderFactory.scala:43) at med.lib.service.keycloak.DSUserStorageProviderFactory.create(DSUserStorageProviderFactory.scala:19) at org.keycloak.storage.UserStorageManager.getStorageProviderInstance(UserStorageManager.java:92) at org.keycloak.storage.UserStorageManager.getEnabledStorageProviders(UserStorageManager.java:130) at org.keycloak.storage.UserStorageManager.getUserByEmail(UserStorageManager.java:407) at org.keycloak.models.cache.infinispan.UserCacheSession.getUserByEmail(UserCacheSession.java:380) at org.keycloak.models.utils.KeycloakModelUtils.findUserByNameOrEmail(KeycloakModelUtils.java:207) at org.keycloak.authentication.authenticators.browser.AbstractUsernameFormAuthenticator.validateUserAndPassword(AbstractUsernameFormAuthenticator.java:148) at org.keycloak.authentication.authenticators.browser.UsernamePasswordForm.validateForm(UsernamePasswordForm.java:55) at org.keycloak.authentication.authenticators.browser.UsernamePasswordForm.action(UsernamePasswordForm.java:48) at org.keycloak.authentication.DefaultAuthenticationFlow.processAction(DefaultAuthenticationFlow.java:113) at org.keycloak.authentication.DefaultAuthenticationFlow.processAction(DefaultAuthenticationFlow.java:97) at org.keycloak.authentication.AuthenticationProcessor.authenticationAction(AuthenticationProcessor.java:873) at org.keycloak.services.resources.LoginActionsService.processFlow(LoginActionsService.java:292) at org.keycloak.services.resources.LoginActionsService.processAuthentication(LoginActionsService.java:263) at org.keycloak.services.resources.LoginActionsService.authenticate(LoginActionsService.java:259) at org.keycloak.services.resources.LoginActionsService.authenticateForm(LoginActionsService.java:320) at sun.reflect.GeneratedMethodAccessor701.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:139) at org.jboss.resteasy.core.ResourceMethodInvoker.internalInvokeOnTarget(ResourceMethodInvoker.java:510) at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTargetAfterFilter(ResourceMethodInvoker.java:400) at org.jboss.resteasy.core.ResourceMethodInvoker.lambda$invokeOnTarget$0(ResourceMethodInvoker.java:364) at org.jboss.resteasy.core.interception.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:355) at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTarget(ResourceMethodInvoker.java:366) at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:338) at org.jboss.resteasy.core.ResourceLocatorInvoker.invokeOnTargetObject(ResourceLocatorInvoker.java:137) at org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:100) at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:439) at org.jboss.resteasy.core.SynchronousDispatcher.lambda$invoke$4(SynchronousDispatcher.java:229) at org.jboss.resteasy.core.SynchronousDispatcher.lambda$preprocess$0(SynchronousDispatcher.java:135) at org.jboss.resteasy.core.interception.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:355) at org.jboss.resteasy.core.SynchronousDispatcher.preprocess(SynchronousDispatcher.java:138) at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:215) at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:227) at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:56) at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:51) at javax.servlet.http.HttpServlet.service(HttpServlet.java:791) at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:74) at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129) at org.keycloak.services.filters.KeycloakSessionServletFilter.doFilter(KeycloakSessionServletFilter.java:90) at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84) at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62) at io.undertow.servlet.handlers.ServletChain$1.handleRequest(ServletChain.java:68) at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36) at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:132) at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46) at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64) at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60) at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77) at io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50) at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at org.wildfly.extension.undertow.deployment.GlobalRequestControllerHandler.handleRequest(GlobalRequestControllerHandler.java:68) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:292) at io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:81) at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:138) at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:135) at io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48) at io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43) at org.wildfly.extension.undertow.security.SecurityContextThreadSetupAction.lambda$create$0(SecurityContextThreadSetupAction.java:105) at org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1502) at org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1502) at org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1502) at org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1502) at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:272) at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81) at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:104) at io.undertow.server.Connectors.executeRootHandler(Connectors.java:364) at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:830) at org.jboss.threads.ContextClassLoaderSavingRunnable.run(ContextClassLoaderSavingRunnable.java:35) at org.jboss.threads.EnhancedQueueExecutor.safeRun(EnhancedQueueExecutor.java:1982) at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.doRunTask(EnhancedQueueExecutor.java:1486) at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1377) at java.lang.Thread.run(Thread.java:748) Thanks for your help! Céline Leduc Céline Leduc Software engineer www.libmed.fr Soutenue par : - Le Ministère de l’Enseignement supérieur, de la Recherche et de l’Innovation - BPI France