java.lang.NullPointerException
   at com.sun.deploy.net.proxy.AbstractAutoProxyHandler.isSupportedINSFile(AbstractAutoProxyHandler.java:168)
   at com.sun.deploy.net.proxy.AbstractAutoProxyHandler.init(AbstractAutoProxyHandler.java:135)
   at com.sun.deploy.net.proxy.DynamicProxyManager.reset(DynamicProxyManager.java:338)
   at com.sun.deploy.net.proxy.DeployProxySelector.reset(DeployProxySelector.java:58)
   at com.sun.javaws.Main.initializeExecutionEnvironment(Main.java:1310)
   at com.sun.javaws.Main.continueInSecureThread(Main.java:248)
   at com.sun.javaws.Main.access$000(Main.java:61)
   at com.sun.javaws.Main$1.run(Main.java:160)
   at java.lang.Thread.run(Thread.java:722)

When the proxy file is specified but does not exist. I don't know how to reproduce this in the wild, but here is a test case:

    public void testInvalidProxyFile() throws Exception {
        SetupHelpers.setupServices();
        server = WebServer.startServer(port, null, false);

        proxyInfo = new BrowserProxyInfo();
        serverName = "http://localhost:%d";

        // test.pac is an invalid proxy file.
        proxyFileName = getServerName() + "/test.pac";
        proxyInfo.setAutoConfigURL(proxyFileName);
        proxyInfo.setType(ProxyType.AUTO);

        proxyHandler = createProxyHandlerForPlatform();

        try {
            proxyHandler.init(proxyInfo);
            ProxyInfo pi[] = proxyHandler.getProxyInfo(
                new URL("http://callalert.some.domain/hello.jar"));
            assertEquals("Expect list of 2 proxies", 2, pi.length);
        }
        catch (NullPointerException e) {
            fail("Failed to initialize proxy handler");
        }
    }