Common error - com.vaadin.event.ListenerMethod - why?

[kethur]

I am unable to attach my XML file(or any file for that matter to this post)  that i am trying to deploy.  But, the below error is very common i encountered many times.  It does not tell you what the problem is.  No clue whatsoever.  So, hopefully Activiti guys will be handling errors better. 

I basically could deploy my zip file (contains a bpmn.xml and a form file).  when i click on myinstances > click on my process it gives me the below error in the console and i can not see the process diagram in my explorer.  In a successful scenario i should be able to see what stage the current workflow is in. 

could someone help what this error actually means (or related to) so, it can avoid lot of my headaches? 

Many thanks,.

12-Oct-2012 17:42:57 org.activiti.engine.impl.bpmn.deployer.BpmnDeployer deploy
INFO: Processing resource documentReview.form
12-Oct-2012 17:43:28 com.vaadin.Application terminalError
SEVERE: Terminal error:
com.vaadin.event.ListenerMethod$MethodException
Cause: java.lang.NullPointerException
        at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:510)
        at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:164)
        at com.vaadin.ui.AbstractComponent.fireEvent(AbstractComponent.java:1193)
        at com.vaadin.ui.AbstractField.fireValueChange(AbstractField.java:891)
        at com.vaadin.ui.AbstractField.setValue(AbstractField.java:529)
        at com.vaadin.ui.AbstractSelect.setValue(AbstractSelect.java:666)
        at com.vaadin.ui.AbstractSelect.changeVariables(AbstractSelect.java:475)
        at com.vaadin.ui.Table.changeVariables(Table.java:2038)
        at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.handleVariableBurst(AbstractCommunicationManager.java:1299)
        at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.handleVariables(AbstractCommunicationManager.java:1219)
        at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.doHandleUidlRequest(AbstractCommunicationManager.java:735)
        at com.vaadin.terminal.gwt.server.CommunicationManager.handleUidlRequest(CommunicationManager.java:296)
        at com.vaadin.terminal.gwt.server.AbstractApplicationServlet.service(AbstractApplicationServlet.java:501)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java: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:191)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
        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:298)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
        at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.NullPointerException
        at org.activiti.explorer.ui.custom.UserProfileLink.initUserLink(UserProfileLink.java:93)
        at org.activiti.explorer.ui.custom.UserProfileLink.<init>(UserProfileLink.java:61)
        at org.activiti.explorer.ui.management.process.ProcessInstanceDetailPanel.getTaskAssigneeComponent(ProcessInstanceDetailPanel.java:270)
        at org.activiti.explorer.ui.management.process.ProcessInstanceDetailPanel.addTaskItem(ProcessInstanceDetailPanel.java:262)
        at org.activiti.explorer.ui.management.process.ProcessInstanceDetailPanel.addTasks(ProcessInstanceDetailPanel.java:230)
        at org.activiti.explorer.ui.management.process.ProcessInstanceDetailPanel.init(ProcessInstanceDetailPanel.java:112)
        at org.activiti.explorer.ui.management.process.ProcessInstanceDetailPanel.<init>(ProcessInstanceDetailPanel.java:98)
        at org.activiti.explorer.ui.process.ProcessInstancePage$1.valueChange(ProcessInstancePage.java:60)
        at sun.reflect.GeneratedMethodAccessor111.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:490)
        … 25 more

[shriraamnl]

Hi there,
I have deployment my process success, when I click the attachment button, the attachment window popsup and i can attach the file, after clicking the button, it throws the error,

Exception
com.vaadin.event.ListenerMethod$MethodException
Cause: com.vaadin.event.ListenerMethod$MethodException
Cause: java.lang.NullPointerException
at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:510)
at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:164)
at com.vaadin.ui.AbstractComponent.fireEvent(AbstractComponent.java:1193)
at com.vaadin.ui.Button.fireClick(Button.java:539)
at com.vaadin.ui.Button.changeVariables(Button.java:206)
at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.handleVariableBurst(AbstractCommunicationManager.java:1299)
at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.handleVariables(AbstractCommunicationManager.java:1219)
at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.doHandleUidlRequest(AbstractCommunicationManager.java:735)
at com.vaadin.terminal.gwt.server.CommunicationManager.handleUidlRequest(CommunicationManager.java:296)
at com.vaadin.terminal.gwt.server.AbstractApplicationServlet.service(AbstractApplicationServlet.java:501)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)
Caused by: com.vaadin.event.ListenerMethod$MethodException
Cause: java.lang.NullPointerException
at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:510)
at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:164)
at com.vaadin.ui.AbstractComponent.fireEvent(AbstractComponent.java:1193)
at org.activiti.explorer.ui.content.CreateAttachmentPopupWindow.saveAttachment(CreateAttachmentPopupWindow.java:201)
at org.activiti.explorer.ui.content.CreateAttachmentPopupWindow$1.buttonClick(CreateAttachmentPopupWindow.java:113)
at sun.reflect.GeneratedMethodAccessor209.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.vaadin.event.Lis
Please help me to fix this bug.
Thanks in advance
Shriraam