# WARN: KC-SERVICES0051: Failed to logout client, continuing: java.lang.NullPointerException

**URL:** <https://forum.keycloak.org/t/warn-kc-services0051-failed-to-logout-client-continuing-java-lang-nullpointerexception/9958>\
**Category:** Miscellanaeous\
**Created:** [July 7, 2021, 11:02am UTC](https://forum.keycloak.org/t/warn-kc-services0051-failed-to-logout-client-continuing-java-lang-nullpointerexception/9958 "2021-07-07T11:02:49Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![c1portalops](https://avatars.discourse-cdn.com/v4/letter/c/a6a055/32.png) [@c1portalops](https://forum.keycloak.org/u/c1portalops)\
**Post date:** [July 7, 2021, 11:02am UTC](https://forum.keycloak.org/t/warn-kc-services0051-failed-to-logout-client-continuing-java-lang-nullpointerexception/9958/1 "2021-07-07T11:02:49Z")

</div>

Hi all!  
We have a standalone deployment of Keycloak 14.0.0.  
We have some clients configured, in a custom realm.  
Our question is about the following warning that appears in server.log, whenever a user log out.  
The user seems that he is logged out and we haven’t noticed anything “bad”.  
Has anyone come across this?  
We were not able to find more info about this.

Many thanks to you all!

2021-07-07 09:24:39,955 WARN [org.keycloak.services] (default task-508) KC-SERVICES0051: Failed to logout client, continuing: java.lang.NullPointerException  
at org.keycloak.keycloak-services@14.0.0//org.keycloak.services.managers.ResourceAdminManager.logoutClientSessionWithBackchannelLogoutUrl(ResourceAdminManager.java:179)  
at org.keycloak.keycloak-services@14.0.0//org.keycloak.protocol.oidc.OIDCLoginProtocol.backchannelLogout(OIDCLoginProtocol.java:333)  
at org.keycloak.keycloak-services@14.0.0//org.keycloak.services.managers.AuthenticationManager.backchannelLogoutClientSession(AuthenticationManager.java:468)  
at org.keycloak.keycloak-services@14.0.0//org.keycloak.services.managers.AuthenticationManager.lambda$browserLogoutAllClients$10(AuthenticationManager.java:619)  
at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)  
at org.keycloak.keycloak-services@14.0.0//org.keycloak.services.managers.AuthenticationManager.browserLogoutAllClients(AuthenticationManager.java:619)  
at org.keycloak.keycloak-services@14.0.0//org.keycloak.services.managers.AuthenticationManager.browserLogout(AuthenticationManager.java:594)  
at org.keycloak.keycloak-services@14.0.0//org.keycloak.protocol.oidc.endpoints.LogoutEndpoint.initiateBrowserLogout(LogoutEndpoint.java:472)  
at org.keycloak.keycloak-services@14.0.0//org.keycloak.protocol.oidc.endpoints.LogoutEndpoint.logout(LogoutEndpoint.java:179)  
at jdk.internal.reflect.GeneratedMethodAccessor1044.invoke(Unknown Source)  
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)  
at java.base/java.lang.reflect.Method.invoke(Method.java:567)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:138)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.ResourceMethodInvoker.internalInvokeOnTarget(ResourceMethodInvoker.java:546)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTargetAfterFilter(ResourceMethodInvoker.java:435)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.ResourceMethodInvoker.lambda$invokeOnTarget$0(ResourceMethodInvoker.java:396)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.interception.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:358)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTarget(ResourceMethodInvoker.java:398)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:365)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.ResourceLocatorInvoker.invokeOnTargetObject(ResourceLocatorInvoker.java:150)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:110)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.ResourceLocatorInvoker.invokeOnTargetObject(ResourceLocatorInvoker.java:141)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:104)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:440)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.SynchronousDispatcher.lambda$invoke$4(SynchronousDispatcher.java:229)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.SynchronousDispatcher.lambda$preprocess$0(SynchronousDispatcher.java:135)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.interception.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:358)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.SynchronousDispatcher.preprocess(SynchronousDispatcher.java:138)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:215)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:245)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:61)  
at org.jboss.resteasy.resteasy-jaxrs@3.15.1.Final//org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:56)  
at javax.servlet.api@2.0.0.Final//javax.servlet.http.HttpServlet.service(HttpServlet.java:590)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:74)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129)  
at org.keycloak.keycloak-wildfly-extensions@14.0.0//org.keycloak.provider.wildfly.WildFlyRequestFilter.lambda$doFilter$0(WildFlyRequestFilter.java:41)  
at org.keycloak.keycloak-services@14.0.0//org.keycloak.services.filters.AbstractRequestFilter.filter(AbstractRequestFilter.java:43)  
at org.keycloak.keycloak-wildfly-extensions@14.0.0//org.keycloak.provider.wildfly.WildFlyRequestFilter.doFilter(WildFlyRequestFilter.java:39)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.ServletChain$1.handleRequest(ServletChain.java:68)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)  
at org.wildfly.extension.undertow@23.0.2.Final//org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)  
at io.undertow.core@2.2.5.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.RedirectDirHandler.handleRequest(RedirectDirHandler.java:68)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:117)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)  
at io.undertow.core@2.2.5.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)  
at io.undertow.core@2.2.5.Final//io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)  
at io.undertow.core@2.2.5.Final//io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77)  
at io.undertow.core@2.2.5.Final//io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50)  
at io.undertow.core@2.2.5.Final//io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)  
at io.undertow.core@2.2.5.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)  
at org.wildfly.extension.undertow@23.0.2.Final//org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)  
at io.undertow.core@2.2.5.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)  
at org.wildfly.extension.undertow@23.0.2.Final//org.wildfly.extension.undertow.deployment.GlobalRequestControllerHandler.handleRequest(GlobalRequestControllerHandler.java:68)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.SendErrorPageHandler.handleRequest(SendErrorPageHandler.java:52)  
at io.undertow.core@2.2.5.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:269)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:78)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:133)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:130)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43)  
at org.wildfly.extension.undertow@23.0.2.Final//org.wildfly.extension.undertow.security.SecurityContextThreadSetupAction.lambda$create$0(SecurityContextThreadSetupAction.java:105)  
at org.wildfly.extension.undertow@23.0.2.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1530)  
at org.wildfly.extension.undertow@23.0.2.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1530)  
at org.wildfly.extension.undertow@23.0.2.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1530)  
at org.wildfly.extension.undertow@23.0.2.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1530)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:249)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:78)  
at io.undertow.servlet@2.2.5.Final//io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:99)  
at io.undertow.core@2.2.5.Final//io.undertow.server.Connectors.executeRootHandler(Connectors.java:387)  
at io.undertow.core@2.2.5.Final//io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:841)  
at org.jboss.threads@2.4.0.Final//org.jboss.threads.ContextClassLoaderSavingRunnable.run(ContextClassLoaderSavingRunnable.java:35)  
at org.jboss.threads@2.4.0.Final//org.jboss.threads.EnhancedQueueExecutor.safeRun(EnhancedQueueExecutor.java:1990)  
at org.jboss.threads@2.4.0.Final//org.jboss.threads.EnhancedQueueExecutor$ThreadBody.doRunTask(EnhancedQueueExecutor.java:1486)  
at org.jboss.threads@2.4.0.Final//org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1377)  
at org.jboss.xnio@3.8.4.Final//org.xnio.XnioWorker$WorkerThreadFactory$1$1.run(XnioWorker.java:1280)  
at java.base/java.lang.Thread.run(Thread.java:835)

2021-07-07 09:24:39,986 WARN [org.keycloak.services.managers.AuthenticationManager] (default task-508) Some clients have been not been logged out for user adminisratore in fubar realm: lala-client