Error after creating users

I created two user accounts and modified one. Then I clicked the Nuxeo logo to go back to the site root. When I clicked the Default server, I got this error.

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: In attribute requires value for component: documentTaskActions.currentItem
org.jboss.seam.servlet.SeamExceptionFilter.doFilter(SeamExceptionFilter.java:61)
org.ajax4jsf.framework.ajax.xmlfilter.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:75)
org.ajax4jsf.framework.ajax.xmlfilter.BaseFilter.doFilter(BaseFilter.java:213)
org.nuxeo.ecm.ui.web.filter.SessionExpirationFilter.doFilter(SessionExpirationFilter.java:78)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

root cause

javax.servlet.ServletException: In attribute requires value for component: documentTaskActions.currentItem
javax.faces.webapp.FacesServlet.service(FacesServlet.java:154)
org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:100)
org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:147)
org.jboss.seam.servlet.SeamRedirectFilter.doFilter(SeamRedirectFilter.java:32)
org.jboss.seam.servlet.SeamExceptionFilter.doFilter(SeamExceptionFilter.java:46)
org.ajax4jsf.framework.ajax.xmlfilter.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:75)
org.ajax4jsf.framework.ajax.xmlfilter.BaseFilter.doFilter(BaseFilter.java:213)
org.nuxeo.ecm.ui.web.filter.SessionExpirationFilter.doFilter(SessionExpirationFilter.java:78)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

root cause

org.jboss.seam.RequiredException: In attribute requires value for component: documentTaskActions.currentItem
org.jboss.seam.Component.getInstanceToInject(Component.java:1878)
org.jboss.seam.Component.injectFields(Component.java:1344)
org.jboss.seam.Component.inject(Component.java:1112)
org.jboss.seam.interceptors.BijectionInterceptor.bijectTargetComponent(BijectionInterceptor.java:48)
sun.reflect.GeneratedMethodAccessor134.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
java.lang.reflect.Method.invoke(Unknown Source)
org.jboss.seam.util.Reflections.invoke(Reflections.java:18)
org.jboss.seam.intercept.Interceptor.aroundInvoke(Interceptor.java:169)
org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:64)
org.jboss.seam.interceptors.ConversationInterceptor.endOrBeginLongRunningConversation(ConversationInterceptor.java:51)
sun.reflect.GeneratedMethodAccessor131.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
java.lang.reflect.Method.invoke(Unknown Source)
org.jboss.seam.util.Reflections.invoke(Reflections.java:18)
org.jboss.seam.intercept.Interceptor.aroundInvoke(Interceptor.java:169)
org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:64)
org.jboss.seam.interceptors.BusinessProcessInterceptor.manageBusinessProcessContext(BusinessProcessInterceptor.java:50)
sun.reflect.GeneratedMethodAccessor130.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
java.lang.reflect.Method.invoke(Unknown Source)
org.jboss.seam.util.Reflections.invoke(Reflections.java:18)
org.jboss.seam.intercept.Interceptor.aroundInvoke(Interceptor.java:169)
org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:64)
org.jboss.seam.interceptors.ExceptionInterceptor.handleExceptions(ExceptionInterceptor.java:38)
sun.reflect.GeneratedMethodAccessor129.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
java.lang.reflect.Method.invoke(Unknown Source)
org.jboss.seam.util.Reflections.invoke(Reflections.java:18)
org.jboss.seam.intercept.Interceptor.aroundInvoke(Interceptor.java:169)
org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:64)
org.jboss.seam.interceptors.SynchronizationInterceptor.serialize(SynchronizationInterceptor.java:30)
sun.reflect.GeneratedMethodAccessor128.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
java.lang.reflect.Method.invoke(Unknown Source)
org.jboss.seam.util.Reflections.invoke(Reflections.java:18)
org.jboss.seam.intercept.Interceptor.aroundInvoke(Interceptor.java:169)
org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:64)
org.jboss.seam.intercept.RootInterceptor.createSeamInvocationContext(RootInterceptor.java:144)
org.jboss.seam.intercept.RootInterceptor.invokeInContexts(RootInterceptor.java:129)
org.jboss.seam.intercept.RootInterceptor.invoke(RootInterceptor.java:102)
org.jboss.seam.intercept.JavaBeanInterceptor.interceptInvocation(JavaBeanInterceptor.java:144)
org.jboss.seam.intercept.JavaBeanInterceptor.intercept(JavaBeanInterceptor.java:79)
org.nuxeo.ecm.platform.ec.workflow.web.listener.ejb.DocumentTaskActionsBean$$EnhancerByCGLIB$$6ddf7607.toString(<generated>)
com.sun.facelets.util.DevTools.writeVariables(DevTools.java:168)
com.sun.facelets.util.DevTools.writeVariables(DevTools.java:147)
com.sun.facelets.util.DevTools.debugHtml(DevTools.java:109)
com.sun.facelets.FaceletViewHandler.handleRenderException(FaceletViewHandler.java:677)
com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:646)
org.ajax4jsf.framework.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:101)
org.ajax4jsf.framework.ajax.AjaxViewHandler.renderView(AjaxViewHandler.java:222)
org.apache.myfaces.lifecycle.RenderResponseExecutor.execute(RenderResponseExecutor.java:41)
org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:132)
javax.faces.webapp.FacesServlet.service(FacesServlet.java:140)
org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:100)
org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:147)
org.jboss.seam.servlet.SeamRedirectFilter.doFilter(SeamRedirectFilter.java:32)
org.jboss.seam.servlet.SeamExceptionFilter.doFilter(SeamExceptionFilter.java:46)
org.ajax4jsf.framework.ajax.xmlfilter.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:75)
org.ajax4jsf.framework.ajax.xmlfilter.BaseFilter.doFilter(BaseFilter.java:213)
org.nuxeo.ecm.ui.web.filter.SessionExpirationFilter.doFilter(SessionExpirationFilter.java:78)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)