Java Web Start application fails to start on JRE6u10 b14 (beta) with
java.lang.AssertionError after authentication attempt.
The Java Web Start Error message is:
Application Error: Unable to launch the application


The Exception tab shows:

java.lang.AssertionError
   at sun.net.www.protocol.http.AuthenticationInfo.requestCompleted(Unknown Source)
   at sun.net.www.protocol.http.AuthenticationInfo.endAuthRequest(Unknown Source)
   at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
   at java.net.HttpURLConnection.getResponseCode(Unknown Source)
   at com.sun.deploy.net.BasicHttpRequest.doRequest(Unknown Source)
   at com.sun.deploy.net.BasicHttpRequest.doGetRequestEX(Unknown Source)
   at com.sun.deploy.net.DownloadEngine.actionDownload(Unknown Source)
   at com.sun.deploy.net.DownloadEngine.getCacheEntry(Unknown Source)
   at com.sun.deploy.net.DownloadEngine.getResourceCacheEntry(Unknown Source)
   at com.sun.deploy.net.DownloadEngine.getResourceCacheEntry(Unknown Source)
   at com.sun.deploy.net.DownloadEngine.getResource(Unknown Source)
   at com.sun.deploy.net.DownloadEngine.getResource(Unknown Source)
   at com.sun.javaws.Launcher.updateFinalLaunchDesc(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$1.run(Unknown Source)
   at java.lang.Thread.run(Unknown Source)


The problem is strictly reproducible.