Java Webstart fails to launch

I can only find JWS for the 4.0.1 version, not 4.6.1, and when I launch 4.0.1 on a Mac with 10.8 and Java 7 I get the following error

java.lang.SecurityException: com.sun.deploy.net.JARSigningException: Found unsigned entry in resource: http://www.soapui.org/jnlp/SNAPSHOT/activation-1.1.jar
at com.sun.deploy.cache.CacheEntry.getJarFile(Unknown Source)
at com.sun.javaws.security.SigningInfo.check(Unknown Source)
at com.sun.javaws.security.JNLPSignedResourcesHelper.checkSignedResourcesHelper(Unknown Source)
at com.sun.javaws.security.JNLPSignedResourcesHelper.checkSignedResources(Unknown Source)
at com.sun.javaws.Launcher.prepareResources(Unknown Source)
at com.sun.javaws.Launcher.prepareAllResources(Unknown Source)
at com.sun.javaws.Launcher.prepareToLaunch(Unknown Source)
at com.sun.javaws.Launcher.prepareToLaunch(Unknown Source)
at com.sun.javaws.Launcher.launch(Unknown Source)
at com.sun.javaws.Main.launchApp(Unknown Source)
at com.sun.javaws.Main.continueInSecureThread(Unknown Source)
at com.sun.javaws.Main.access$000(Unknown Source)
at com.sun.javaws.Main$1.run(Unknown Source)
at java.lang.Thread.run(Thread.java:744)
Caused by: com.sun.deploy.net.JARSigningException: Found unsigned entry in resource: http://www.soapui.org/jnlp/SNAPSHOT/activation-1.1.jar

Where can I find a webstart version that works?