Hello everyone,
I have been trying to find out the causes of this error and as I haven't and also didn't find any post mentioning it, I'm posting it here.
In Teamsite, in the Administration Panel, when trying to give a user specific deployment permissions, I am getting this error when clicking "Save":

The only log reporting this is /ApplicationContainer/standalone/log/iwjboss.log
This is the stack trace:
16:32:37,577 ERROR [io.undertow.request] (default task-8) UT005023: Exception handling request to /iw-admin/action/edit_user: org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:894) [org.springframework.web.servlet-3.1.1.RELEASE.jar:3.1.1.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:789) [org.springframework.web.servlet-3.1.1.RELEASE.jar:3.1.1.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707) [jboss-servlet-api_3.1_spec-1.0.0.Final.jar:1.0.0.Final]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) [jboss-servlet-api_3.1_spec-1.0.0.Final.jar:1.0.0.Final]
at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:130) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at com.interwoven.ui.core.auth.AuthenticationFilter.doFilter(AuthenticationFilter.java:281) [core.jar:8.0.5.0.0 Build 9]
at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346) [org.springframework.web-3.1.1.RELEASE.jar:3.1.1.RELEASE]
at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:259) [org.springframework.web-3.1.1.RELEASE.jar:3.1.1.RELEASE]
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:132) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) [org.springframework.web-3.1.1.RELEASE.jar:3.1.1.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) [org.springframework.web-3.1.1.RELEASE.jar:3.1.1.RELEASE]
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:132) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:85) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:61) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:56) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:45) [undertow-core-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:61) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:58) [undertow-core-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:70) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.security.handlers.SecurityInitialHandler.handleRequest(SecurityInitialHandler.java:76) [undertow-core-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Beta5.jar:1.1.0.Beta5]
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.Beta5.jar:1.1.0.Beta5]
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:247) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:234) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:76) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:153) [undertow-servlet-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.server.Connectors.executeRootHandler(Connectors.java:197) [undertow-core-1.1.0.Beta5.jar:1.1.0.Beta5]
at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:737) [undertow-core-1.1.0.Beta5.jar:1.1.0.Beta5]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_67]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_67]
at java.lang.Thread.run(Thread.java:745) [rt.jar:1.7.0_67]
Caused by: java.lang.NullPointerException
at com.interwoven.ui.admin.usermgmt.users.action.EditUserController.handle(EditUserController.java:287) [admin.jar:7.4.1.0.0 Build 367]
at org.springframework.web.servlet.mvc.AbstractCommandController.handleRequestInternal(AbstractCommandController.java:87) [org.springframework.web.servlet-3.1.1.RELEASE.jar:3.1.1.RELEASE]
at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:153) [org.springframework.web.servlet-3.1.1.RELEASE.jar:3.1.1.RELEASE]
at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:48) [org.springframework.web.servlet-3.1.1.RELEASE.jar:3.1.1.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:923) [org.springframework.web.servlet-3.1.1.RELEASE.jar:3.1.1.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852) [org.springframework.web.servlet-3.1.1.RELEASE.jar:3.1.1.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882) [org.springframework.web.servlet-3.1.1.RELEASE.jar:3.1.1.RELEASE]
... 40 more
I would really appreciate any kind of advice.
Regards