Hi, I had once a similiar issue... Have a look at the module.xml file in:  modules\system\layers\base\org\keycloak\keycloak-undertow-adapter\main Is the module org.jboss.xnio listed in the dependencies section? Best Michael Am 04. Februar 2015 um 16:47 schrieb Pablo N <panulab(a)gmail.com&gt;: Hello, I was running my web application in Wildfly 8.2 and Keycloak 1.0.4.Final and everything worked as expected. After updating Keycloak to version 1.1.0.Final (also wildfly adapter version) I get the following error when I try to access my application: 08:32:41,271 ERROR [io.undertow.request] (default task-11) UT005023: Exception handling request to /gui/main/home: java.lang.NoClassDefFo undError: org/xnio/OptionMap         at org.keycloak.adapters.undertow.SavedRequest.trySaveRequest(SavedRequest.java:49) [keycloak-undertow-adapter-1.1.0.Final.jar:1.1.0.Fina l]         at org.keycloak.adapters.undertow.ServletSessionTokenStore.saveRequest(ServletSessionTokenStore.java:111) [keycloak-undertow-adapter-1.1. 0.Final.jar:1.1.0.Final]         at org.keycloak.adapters.OAuthRequestAuthenticator$2.challenge(OAuthRequestAuthenticator.java:182) [keycloak-adapter-core-1.1.0.Final.jar :1.1.0.Final]         at org.keycloak.adapters.undertow.AbstractUndertowKeycloakAuthMech.sendChallenge(AbstractUndertowKeycloakAuthMech.java:68) [keycloak-unde rtow-adapter-1.1.0.Final.jar:1.1.0.Final]         at io.undertow.security.impl.SecurityContextImpl$ChallengeSender.transition(SecurityContextImpl.java:330) [undertow-core-1.1.0.Final.jar: 1.1.0.Final]         at io.undertow.security.impl.SecurityContextImpl$ChallengeSender.transition(SecurityContextImpl.java:349) [undertow-core-1.1.0.Final.jar: 1.1.0.Final]         at io.undertow.security.impl.SecurityContextImpl$ChallengeSender.access$300(SecurityContextImpl.java:314) [undertow-core-1.1.0.Final.jar: 1.1.0.Final]         at io.undertow.security.impl.SecurityContextImpl.sendChallenges(SecurityContextImpl.java:135) [undertow-core-1.1.0.Final.jar:1.1.0.Final]         at io.undertow.security.impl.SecurityContextImpl.authTransition(SecurityContextImpl.java:109) [undertow-core-1.1.0.Final.jar:1.1.0.Final]         at io.undertow.security.impl.SecurityContextImpl.authTransition(SecurityContextImpl.java:114) [undertow-core-1.1.0.Final.jar:1.1.0.Final]         at io.undertow.security.impl.SecurityContextImpl.authenticate(SecurityContextImpl.java:99) [undertow-core-1.1.0.Final.jar:1.1.0.Final]         at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:54) [undert ow-servlet-1.1.0.Final.jar:1.1.0.Final]         at io.undertow.server.handlers.DisableCacheHandler.handleRequest(DisableCacheHandler.java:33) [undertow-core-1.1.0.Final.jar:1.1.0.Final]         at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Final.jar:1.1.0.Final]         at io.undertow.security.handlers.AuthenticationConstraintHandler.handleRequest(AuthenticationConstraintHandler.java:51) [undertow-core-1. 1.0.Final.jar:1.1.0.Final]         at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:45) [undertow-core-1.1. 0.Final.jar:1.1.0.Final]         at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.ja va:63) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]         at io.undertow.servlet.handlers.security.ServletSecurityConstraintHandler.handleRequest(ServletSecurityConstraintHandler.java:56) [undert ow-servlet-1.1.0.Final.jar:1.1.0.Final]         at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:58) [undertow-core-1. 1.0.Final.jar:1.1.0.Final]         at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:70) [unde rtow-servlet-1.1.0.Final.jar:1.1.0.Final]         at io.undertow.security.handlers.SecurityInitialHandler.handleRequest(SecurityInitialHandler.java:76) [undertow-core-1.1.0.Final.jar:1.1. 0.Final]         at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Final.jar:1.1.0.Final]         at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)         at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Final.jar:1.1.0.Final]         at org.keycloak.adapters.undertow.ServletPreAuthActionsHandler.handleRequest(ServletPreAuthActionsHandler.java:69) [keycloak-undertow-ada pter-1.1.0.Final.jar:1.1.0.Final]         at org.keycloak.adapters.undertow.ServletPreAuthActionsHandler.handleRequest(ServletPreAuthActionsHandler.java:69) [keycloak-undertow-ada pter-1.1.0.Final.jar:1.1.0.Final]         at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Final.jar:1.1.0.Final]         at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:261) [undertow-servlet-1.1.0.Final.ja r:1.1.0.Final]         at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:247) [undertow-servlet-1.1.0.Final.jar:1 .1.0.Final]         at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:76) [undertow-servlet-1.1.0.Final.jar:1.1.0.F inal]         at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:166) [undertow-servlet-1.1.0.Final.jar:1 .1.0.Final]         at io.undertow.server.Connectors.executeRootHandler(Connectors.java:197) [undertow-core-1.1.0.Final.jar:1.1.0.Final]         at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:759) [undertow-core-1.1.0.Final.jar:1.1.0.Final]         at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [rt.jar:1.8.0_11]         at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [rt.jar:1.8.0_11]         at java.lang.Thread.run(Thread.java:745) [rt.jar:1.8.0_11] Caused by: java.lang.ClassNotFoundException: org.xnio.OptionMap from [Module "deployment.gui-web-0.14.0-SNAPSHOT.war:main" from Service M odule Loader]         at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:213) [jboss-modules.jar:1.3.3.Final]         at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:459) [jboss-modules.jar:1.3.3.Final]         at org.jboss.modules.ConcurrentClassLoader.performLoadClassChecked(ConcurrentClassLoader.java:408) [jboss-modules.jar:1.3.3.Final]         at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:389) [jboss-modules.jar:1.3.3.Final]         at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:134) [jboss-modules.jar:1.3.3.Final]         ... 36 more As I can see this error was discovered and solved (https://issues.jboss.org/browse/KEYCLOAK-899) so I dont know if any migration change is pending from my side. Thank you very much for your help _______________________________________________ keycloak-user mailing list keycloak-user(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/keycloak-user