The startup class is not packaged in a jar file

I use myeclipse to develop spark plug.when I start spark program,everything is normal and there is no information in console.But when I click login out ,there is a problem that The startup class is not packaged in a jar file which was shown in console.I check the folder of lib which is located in target/build,there has a startup.jar file.Here is the detail:

十月 13, 2015 8:44:06 上午 org.jivesoftware.spark.util.log.Log error

严重: The startup class is not packaged in a jar file

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException

    at org.jivesoftware.MainWindow.getCommandPath(MainWindow.java:386)

    at org.jivesoftware.MainWindow.restartApplicationWithScript(MainWindow.java:393)

    at org.jivesoftware.MainWindow.closeConnectionAndInvoke(MainWindow.java:351)

    at org.jivesoftware.MainWindow.logout(MainWindow.java:330)

    at org.jivesoftware.MainWindow$3.actionPerformed(MainWindow.java:501)

    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)

    at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)

    at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)

    at javax.swing.DefaultButtonModel.setPressed(Unknown Source)

    at javax.swing.AbstractButton.doClick(Unknown Source)

    at javax.swing.plaf.basic.BasicMenuItemUI.doClick(Unknown Source)

    at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(Unknown Source)

    at java.awt.Component.processMouseEvent(Unknown Source)

    at javax.swing.JComponent.processMouseEvent(Unknown Source)

    at java.awt.Component.processEvent(Unknown Source)

    at java.awt.Container.processEvent(Unknown Source)

    at java.awt.Component.dispatchEventImpl(Unknown Source)

    at java.awt.Container.dispatchEventImpl(Unknown Source)

    at java.awt.Component.dispatchEvent(Unknown Source)

    at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)

    at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)

    at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)

    at java.awt.Container.dispatchEventImpl(Unknown Source)

    at java.awt.Window.dispatchEventImpl(Unknown Source)

    at java.awt.Component.dispatchEvent(Unknown Source)

    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)

    at java.awt.EventQueue.access$300(Unknown Source)

    at java.awt.EventQueue$3.run(Unknown Source)

    at java.awt.EventQueue$3.run(Unknown Source)

    at java.security.AccessController.doPrivileged(Native Method)

    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)

    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)

    at java.awt.EventQueue$4.run(Unknown Source)

    at java.awt.EventQueue$4.run(Unknown Source)

    at java.security.AccessController.doPrivileged(Native Method)

    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)

    at java.awt.EventQueue.dispatchEvent(Unknown Source)

    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)

    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)

    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)

    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)

    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)

    at java.awt.EventDispatchThread.run(Unknown Source)