Why does the JBoss SPNEGOLoginModule throw a "LoginException: Continuation Required" error?

Issue

• Why does the JBoss SPNEGOLoginModule throw a "LoginException: Continuation Required" error?

2012-05-03 00:31:14,679 DEBUG [org.jboss.security.negotiation.spnego.SPNEGOLoginModule] (http-10.10.10.10-8080-1) Logged in 'host' LoginContext
2012-05-03 00:31:14,679 TRACE [org.jboss.security.negotiation.spnego.SPNEGOLoginModule] (http-10.10.10.10-8080-1) Result - false
2012-05-03 00:31:14,679 INFO  [STDOUT] (http-10.10.10.10-8080-1)                [Krb5LoginModule]: Entering logout
2012-05-03 00:31:14,679 INFO  [STDOUT] (http-10.10.10.10-8080-1)                [Krb5LoginModule]: logged out Subject
2012-05-03 00:31:14,679 TRACE [org.jboss.security.negotiation.spnego.SPNEGOLoginModule] (http-10.10.10.10-8080-1) super.loginOk false
2012-05-03 00:31:14,679 TRACE [org.jboss.security.negotiation.spnego.SPNEGOLoginModule] (http-10.10.10.10-8080-1) abort
2012-05-03 00:31:14,679 TRACE [org.jboss.security.auth.spi.UsersRolesLoginModule] (http-10.10.10.10-8080-1) initialize
2012-05-03 00:31:14,679 TRACE [org.jboss.security.auth.spi.UsersRolesLoginModule] (http-10.10.10.10-8080-1) Security domain: SPNEGO
2012-05-03 00:31:14,679 TRACE [org.jboss.security.auth.spi.UsersRolesLoginModule] (http-10.10.10.10-8080-1) findResource: null
2012-05-03 00:31:14,679 TRACE [org.jboss.security.auth.spi.UsersRolesLoginModule] (http-10.10.10.10-8080-1) Properties file=vfsfile:/home/dehort/dev/java/jboss-eap-5.1/jboss-as/server/default/conf/props/spnego-users.properties, defaults=null
2012-05-03 00:31:14,679 DEBUG [org.jboss.security.auth.spi.UsersRolesLoginModule] (http-10.10.10.10-8080-1) Loaded properties, users=[]
2012-05-03 00:31:14,680 TRACE [org.jboss.security.auth.spi.UsersRolesLoginModule] (http-10.10.10.10-8080-1) findResource: null
2012-05-03 00:31:14,680 TRACE [org.jboss.security.auth.spi.UsersRolesLoginModule] (http-10.10.10.10-8080-1) Properties file=vfsfile:/home/dehort/dev/java/jboss-eap-5.1/jboss-as/server/default/conf/props/spnego-roles.properties, defaults=null
2012-05-03 00:31:14,680 DEBUG [org.jboss.security.auth.spi.UsersRolesLoginModule] (http-10.10.10.10-8080-1) Loaded properties, users=[Administrator@DEHORT-DOMAIN.GSSLAB.RDU.REDHAT.COM]
2012-05-03 00:31:14,680 TRACE [org.jboss.security.auth.spi.UsersRolesLoginModule] (http-10.10.10.10-8080-1) abort
2012-05-03 00:31:14,680 TRACE [org.jboss.security.plugins.auth.JaasSecurityManagerBase.SPNEGO] (http-10.10.10.10-8080-1) Login failure
javax.security.auth.login.LoginException: Continuation Required.
        at org.jboss.security.negotiation.spnego.SPNEGOLoginModule.login(SPNEGOLoginModule.java:172)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at javax.security.auth.login.LoginContext.invoke(LoginContext.java:769)
        at javax.security.auth.login.LoginContext.access$000(LoginContext.java:186)
        at javax.security.auth.login.LoginContext$4.run(LoginContext.java:683)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.login.LoginContext.invokePriv(LoginContext.java:680)
        at javax.security.auth.login.LoginContext.login(LoginContext.java:579)
        at org.jboss.security.plugins.auth.JaasSecurityManagerBase.defaultLogin(JaasSecurityManagerBase.java:553)
        at org.jboss.security.plugins.auth.JaasSecurityManagerBase.authenticate(JaasSecurityManagerBase.java:487)
        at org.jboss.security.plugins.auth.JaasSecurityManagerBase.isValid(JaasSecurityManagerBase.java:365)
        at org.jboss.security.plugins.JaasSecurityManager.isValid(JaasSecurityManager.java:160)
        at org.jboss.web.tomcat.security.JBossWebRealm.authenticate(JBossWebRealm.java:399)
        at org.jboss.security.negotiation.NegotiationAuthenticator.authenticate(NegotiationAuthenticator.java:127)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:491)
        at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:95)
        at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.process(SecurityContextEstablishmentValve.java:126)
        at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.invoke(SecurityContextEstablishmentValve.java:70)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
        at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:158)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:330)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:829)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:598)