# Error processing request **URL:** \ **Category:** Getting advice\ **Created:** [March 27, 2020, 1:03pm UTC](https://forum.keycloak.org/t/error-processing-request/1859 "2020-03-27T13:03:56Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![titan1975](https://yyz2.discourse-cdn.com/free1/user_avatar/forum.keycloak.org/titan1975/32/551_2.png) [@titan1975](https://forum.keycloak.org/u/titan1975)\ **Post date:** [March 27, 2020, 1:03pm UTC](https://forum.keycloak.org/t/error-processing-request/1859/1 "2020-03-27T13:03:56Z")
Hello I have an spring boot 2 application running on keykloak 9.0.2, wildfly 18 , jdk 11 , eclipse , when i am adding org.keycloak keycloak-spring-boot-starter 9.0.2 application.properties server.connection-timeout=5000 spring.freemarker.cache=false server.port = 8080 keycloak.realm=his keycloak.auth-server-url=http://localhost:8180/auth keycloak.ssl-required=external keycloak.resource=mem keycloak.public-client=false keycloak.credentials.secret=secret keycloak.securityConstraints[0].authRoles[0] = user keycloak.securityConstraints[0].securityCollections[0].name = mem keycloak.securityConstraints[0].securityCollections[0].patterns[0] = /\* # This configuration enables the policy enforcer in order to protect resources served by this application. # During the boot, the policy enforcer is going to fetch all protected resources in Keycloak and automatically configure your application. # Note that protected resources in Keycloak are defined with a URI which maps to a set of resources in this application. keycloak.policy-enforcer-config.on-deny-redirect-to=/accessDenied # Turn off the logs logging.level.root=OFF logging.level.org.springframework.boot=OFF spring.main.banner-mode=OFF on the pom.xml and trying to make a get request I got the below Error, what is wrong ? i cant figure it out. Please can anyone help? Context Path:/nx-2.2.4.RELEASE Servlet Path:/mem Path Info:null Query String:null Stack Trace: java.lang.LinkageError: loader constraint violation: when resolving method “org.keycloak.adapters.PreAuthActionsHandler.(Lorg/keycloak/adapters/spi/UserSessionManagement;Lorg/keycloak/adapters/AdapterDeploymentContext;Lorg/keycloak/adapters/spi/HttpFacade;)V” the class loader ‘deployment.nx-2.2.4.RELEASE.war’ @6f5b0bde (instance of org.jboss.modules.ModuleClassLoader, child of ‘app’ jdk.internal.loader.ClassLoaders$AppClassLoader) of the current class, org/keycloak/adapters/undertow/ServletPreAuthActionsHandler, and the class loader ‘org.keycloak.keycloak-adapter-core@9.0.2’ @5998d957 (instance of org.jboss.modules.ModuleClassLoader, child of ‘app’ jdk.internal.loader.ClassLoaders$AppClassLoader) for the method’s defining class, org/keycloak/adapters/PreAuthActionsHandler, have different Class objects for the type org/keycloak/adapters/spi/HttpFacade used in the signature at deployment.nx-2.2.4.RELEASE.war//org.keycloak.adapters.undertow.ServletPreAuthActionsHandler.handleRequest(ServletPreAuthActionsHandler.java:67) at io.undertow.core@2.0.27.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at io.undertow.servlet@2.0.27.Final//io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:269) at io.undertow.servlet@2.0.27.Final//io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:78) at io.undertow.servlet@2.0.27.Final//io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:133) at io.undertow.servlet@2.0.27.Final//io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:130) at io.undertow.servlet@2.0.27.Final//io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48) at io.undertow.servlet@2.0.27.Final//io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43) at org.wildfly.extension.undertow@18.0.1.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1504) at org.wildfly.extension.undertow@18.0.1.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1504) at org.wildfly.extension.undertow@18.0.1.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1504) at org.wildfly.extension.undertow@18.0.1.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1504) at org.wildfly.extension.undertow@18.0.1.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1504) at io.undertow.servlet@2.0.27.Final//io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:249) at io.undertow.servlet@2.0.27.Final//io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:78) at io.undertow.servlet@2.0.27.Final//io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:99) at io.undertow.core@2.0.27.Final//io.undertow.server.Connectors.executeRootHandler(Connectors.java:376) at io.undertow.core@2.0.27.Final//io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:830) at org.jboss.threads@2.3.3.Final//org.jboss.threads.ContextClassLoaderSavingRunnable.run(ContextClassLoaderSavingRunnable.java:35) at org.jboss.threads@2.3.3.Final//org.jboss.threads.EnhancedQueueExecutor.safeRun(EnhancedQueueExecutor.java:1982) at org.jboss.threads@2.3.3.Final//org.jboss.threads.EnhancedQueueExecutor$ThreadBody.doRunTask(EnhancedQueueExecutor.java:1486) at org.jboss.threads@2.3.3.Final//org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1377) at java.base/java.lang.Thread.run(Thread.java:834) Which I can’t solve, what this is about? It appears when i add the