Trying to take all documents offline for some folders results in stacktrace and no documents take offline

Reproduction:

1) Start essential archetype, make sure there is some content
2) login into cms
3) navigate to 'gettingstarted' folder (root channel folder)
4) then choose for 'take offline all in folder'

Result: See stacktrace below

If you add 'blogs' to essentials, and then try to 'take all offline' for blogs, the same error and stacktrace is the result

[INFO] [talledLocalContainer] 24.12.2015 15:26:34 ERROR http-nio-8080-exec-9 [DefaultExceptionMapper.mapUnexpectedExceptions:170] Unexpected error occurred
[INFO] [talledLocalContainer] org.apache.wicket.WicketRuntimeException: Method onRequest of interface org.apache.wicket.behavior.IBehaviorListener targeted at org.hippoecm.addon.workflow.MenuLink$2@74842c14 on component [MenuLink [Component id = link]] threw an exception
[INFO] [talledLocalContainer] at org.apache.wicket.RequestListenerInterface.internalInvoke(RequestListenerInterface.java:268)
[INFO] [talledLocalContainer] at org.apache.wicket.RequestListenerInterface.invoke(RequestListenerInterface.java:241)
[INFO] [talledLocalContainer] at org.apache.wicket.core.request.handler.ListenerInterfaceRequestHandler.invokeListener(ListenerInterfaceRequestHandler.java:250)
[INFO] [talledLocalContainer] at org.apache.wicket.core.request.handler.ListenerInterfaceRequestHandler.respond(ListenerInterfaceRequestHandler.java:236)
[INFO] [talledLocalContainer] at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:890)
[INFO] [talledLocalContainer] at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64)
[INFO] [talledLocalContainer] at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:261)
[INFO] [talledLocalContainer] at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:218)
[INFO] [talledLocalContainer] at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:289)
[INFO] [talledLocalContainer] at org.apache.wicket.protocol.http.WicketFilter.processRequestCycle(WicketFilter.java:259)
[INFO] [talledLocalContainer] at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:201)
[INFO] [talledLocalContainer] at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:282)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.plugins.login.ConcurrentLoginFilter.doFilter(ConcurrentLoginFilter.java:54)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
[INFO] [talledLocalContainer] at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
[INFO] [talledLocalContainer] at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
[INFO] [talledLocalContainer] at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
[INFO] [talledLocalContainer] at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
[INFO] [talledLocalContainer] at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
[INFO] [talledLocalContainer] at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:617)
[INFO] [talledLocalContainer] at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
[INFO] [talledLocalContainer] at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
[INFO] [talledLocalContainer] at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
[INFO] [talledLocalContainer] at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668)
[INFO] [talledLocalContainer] at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1521)
[INFO] [talledLocalContainer] at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1478)
[INFO] [talledLocalContainer] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
[INFO] [talledLocalContainer] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
[INFO] [talledLocalContainer] at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
[INFO] [talledLocalContainer] at java.lang.Thread.run(Thread.java:745)
[INFO] [talledLocalContainer] Caused by: java.lang.reflect.InvocationTargetException
[INFO] [talledLocalContainer] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[INFO] [talledLocalContainer] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
[INFO] [talledLocalContainer] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[INFO] [talledLocalContainer] at java.lang.reflect.Method.invoke(Method.java:497)
[INFO] [talledLocalContainer] at org.apache.wicket.RequestListenerInterface.internalInvoke(RequestListenerInterface.java:258)
[INFO] [talledLocalContainer] ... 32 more
[INFO] [talledLocalContainer] Caused by: java.lang.NullPointerException
[INFO] [talledLocalContainer] at org.hippoecm.frontend.plugins.reviewedactions.ExtendedFolderWorkflowPlugin$ConfirmBulkWorkflowDialog.loadPublishableDocuments(ExtendedFolderWorkflowPlugin.java:230)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.plugins.reviewedactions.ExtendedFolderWorkflowPlugin$ConfirmBulkWorkflowDialog.loadPublishableDocuments(ExtendedFolderWorkflowPlugin.java:226)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.plugins.reviewedactions.ExtendedFolderWorkflowPlugin$ConfirmBulkWorkflowDialog.<init>(ExtendedFolderWorkflowPlugin.java:193)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.plugins.reviewedactions.ExtendedFolderWorkflowPlugin$2.createRequestDialog(ExtendedFolderWorkflowPlugin.java:139)
[INFO] [talledLocalContainer] at org.hippoecm.addon.workflow.StdWorkflow.invoke(StdWorkflow.java:214)
[INFO] [talledLocalContainer] at org.hippoecm.addon.workflow.ActionDescription.run(ActionDescription.java:92)
[INFO] [talledLocalContainer] at org.hippoecm.addon.workflow.MenuItem$1.onClick(MenuItem.java:50)
[INFO] [talledLocalContainer] at org.hippoecm.addon.workflow.MenuLink$2.onEvent(MenuLink.java:86)
[INFO] [talledLocalContainer] at org.apache.wicket.ajax.AjaxEventBehavior.respond(AjaxEventBehavior.java:146)
[INFO] [talledLocalContainer] at org.apache.wicket.ajax.AbstractDefaultAjaxBehavior.onRequest(AbstractDefaultAjaxBehavior.java:633)
[INFO] [talledLocalContainer] ... 37 more