NullpointerException when started over Java WebStart

Question

I want to start yed over the webstart http://www.yworks.com/products/yed/demo/yed.jnlp. When I launch the jnlp file the application seems to load, but then I get a NullpointerException and the webstart stops.

java.lang.NullPointerException
    at java.util.zip.ZipFile.<init>(Unknown Source)
    at java.util.zip.ZipFile.<init>(Unknown Source)
    at java.util.jar.JarFile.<init>(Unknown Source)
    at java.util.jar.JarFile.<init>(Unknown Source)
    at com.sun.javaws.LaunchDownload.getMainClassName(Unknown Source)
    at com.sun.javaws.Launcher.doLaunchApp(Unknown Source)
    at com.sun.javaws.Launcher.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

Whats wrong here?

Answer 1

It is difficult to tell what went wrong. In any case, this is a Web Start problem, not a yEd problem. Maybe Web Start was not able to download the yEd application. (E.g. because your firewall is blocking the download.) Or maybe an over-zealous anti-virus software deleted the yEd application right after download and before Web Start could run yEd.

The best advice I can offer is to update your Web Start installation to the latest version (8u5 as of this writing) and try again. If that does not help, install yEd locally.