VERY UGLY and very temporary solution: try calling following (below) as soon as possible in your application e.g. at the first line of main method. private static void quickAndDirtyFixForProblemWithWebStartInJava7u25() { if (!1.7.0_25.equals(System.getProperty(java.version))) { return ; } final ClassLoader cl = Thread.currentThread().getContextClassLoader(); try { SwingUtilities.invokeAndWait(