NullPointerException in JAASIdentityManagerImpl

I created RESTful service using RESTeasy. Configured standalone.xml to include custom security domain. Created JPALoginModule which is derived from UsernamePasswordLoginModule. Everything seems to be working fine when I am testing from SOAP UI but in the end of authentication process I am getting the following exception and service is not called:

11:12:36,852 INFO [org.jboss.as] (Controller Boot Thread) JBAS015874: WildFly 8.1.0.CR1 "Kenny" started in 16241ms - Started 1030 of 1118 services (150 services are lazy, passive or on-demand)
11:13:19,710 INFO [org.jboss.ejb.client] (default task-2) JBoss EJB Client version 2.0.1.Final
11:13:21,952 ERROR [io.undertow.request] (default task-2) UT005023: Exception handling request to /vtruespeed/testcontroller/rest/v5/mode: java.lang.RuntimeException: java.lang.NullPointerException
at org.wildfly.extension.undertow.security.JAASIdentityManagerImpl.verifyCredential(JAASIdentityManagerImpl.java:126)
at org.wildfly.extension.undertow.security.JAASIdentityManagerImpl.verify(JAASIdentityManagerImpl.java:82)
at io.undertow.security.impl.BasicAuthenticationMechanism.authenticate(BasicAuthenticationMechanism.java:110) [undertow-core-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.security.impl.SecurityContextImpl$AuthAttempter.transition(SecurityContextImpl.java:281) [undertow-core-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.security.impl.SecurityContextImpl$AuthAttempter.transition(SecurityContextImpl.java:298) [undertow-core-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.security.impl.SecurityContextImpl$AuthAttempter.access$100(SecurityContextImpl.java:268) [undertow-core-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.security.impl.SecurityContextImpl.attemptAuthentication(SecurityContextImpl.java:131) [undertow-core-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.security.impl.SecurityContextImpl.authTransition(SecurityContextImpl.java:106) [undertow-core-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.security.impl.SecurityContextImpl.authenticate(SecurityContextImpl.java:99) [undertow-core-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:54) [undertow-servlet-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.security.handlers.AuthenticationConstraintHandler.handleRequest(AuthenticationConstraintHandler.java:51) [undertow-core-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:45) [undertow-core-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:61) [undertow-servlet-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.servlet.handlers.security.ServletSecurityConstraintHandler.handleRequest(ServletSecurityConstraintHandler.java:56) [undertow-servlet-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:58) [undertow-core-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:70) [undertow-servlet-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.security.handlers.SecurityInitialHandler.handleRequest(SecurityInitialHandler.java:76) [undertow-core-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:25) [undertow-core-1.0.5.Final.jar:1.0.5.Final]
at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:25) [undertow-core-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:25) [undertow-core-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:240) [undertow-servlet-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:227) [undertow-servlet-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:73) [undertow-servlet-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:146) [undertow-servlet-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.server.Connectors.executeRootHandler(Connectors.java:168) [undertow-core-1.0.5.Final.jar:1.0.5.Final]
at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:727) [undertow-core-1.0.5.Final.jar:1.0.5.Final]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_25]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_25]
at java.lang.Thread.run(Thread.java:724) [rt.jar:1.7.0_25]
Caused by: java.lang.NullPointerException
at org.wildfly.extension.undertow.security.AccountImpl.<init>(AccountImpl.java:61)
at org.wildfly.extension.undertow.security.JAASIdentityManagerImpl.verifyCredential(JAASIdentityManagerImpl.java:123)
... 29 more

This is major issue for us.

Thanks,
Stan