Unknown error when drag & drop container in tab and change skin
Show exception:
[ERROR] portal:UIApplication - Error during the processAction phase <java.lang.NullPointerException>
java.lang.NullPointerException
        at org.exoplatform.portal.webui.container.UIContainer$SelectTabActionListener.execute(UICont
ainer.java:85)
        at org.exoplatform.webui.event.Event.broadcast(Event.java:52)
        at org.exoplatform.webui.core.lifecycle.Lifecycle.processAction(Lifecycle.java:63)
        at org.exoplatform.webui.core.UIComponent.processAction(UIComponent.java:90)
        at org.exoplatform.portal.webui.workspace.UIPortalApplicationLifecycle.processAction(UIPorta
lApplicationLifecycle.java:56)
        at org.exoplatform.webui.core.UIComponent.processAction(UIComponent.java:90)
        at org.exoplatform.webui.core.UIApplication.processAction(UIApplication.java:80)
        at org.exoplatform.webui.application.WebuiApplication.processAction(WebuiApplication.java:10
5)
        at org.exoplatform.portal.application.PortalRequestHandler.execute(PortalRequestHandler.java
:87)
        at org.exoplatform.web.WebAppController.service(WebAppController.java:123)
        at org.exoplatform.portal.application.PortalController.service(PortalController.java:92)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.j
ava:290)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:525)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.ja
va:583)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
        at java.lang.Thread.run(Thread.java:595)

[ERROR] portal:UIApplication - Error during the processAction phase <java.lang.NullPointerException>
java.lang.NullPointerException
        at org.exoplatform.portal.webui.container.UIContainer$SelectTabActionListener.execute(UICont
ainer.java:85)
        at org.exoplatform.webui.event.Event.broadcast(Event.java:52)
        at org.exoplatform.webui.core.lifecycle.Lifecycle.processAction(Lifecycle.java:63)
        at org.exoplatform.webui.core.UIComponent.processAction(UIComponent.java:90)
        at org.exoplatform.portal.webui.workspace.UIPortalApplicationLifecycle.processAction(UIPorta
lApplicationLifecycle.java:56)
        at org.exoplatform.webui.core.UIComponent.processAction(UIComponent.java:90)
        at org.exoplatform.webui.core.UIApplication.processAction(UIApplication.java:80)
        at org.exoplatform.webui.application.WebuiApplication.processAction(WebuiApplication.java:10
5)
        at org.exoplatform.portal.application.PortalRequestHandler.execute(PortalRequestHandler.java
:87)
        at org.exoplatform.web.WebAppController.service(WebAppController.java:123)
        at org.exoplatform.portal.application.PortalController.service(PortalController.java:92)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.j
ava:290)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:525)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.ja
va:583)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
        at java.lang.Thread.run(Thread.java:595)