java.lang.NullPointerException
        at org.netbeans.modules.j2ee.appengine.util.AppEnginePluginUtils.getWarChecksum(AppEnginePluginUtils.java:154)
        at org.netbeans.modules.j2ee.appengine.ide.AppEngineDeployer.run(AppEngineDeployer.java:126)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:577)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1030)