During the installation of SilkCentral Manual Testing Client, the following exception is encountered:

java.lang.NullPointerException
                at com.sun.javaws.security.SigningInfo.verifyAllEntriesSigned(Unknown Source)
                at com.sun.javaws.security.SigningInfo.checkSigning(Unknown Source)
                at com.sun.javaws.LaunchDownload.checkSignedResourcesHelper(Unknown Source)
                at com.sun.javaws.LaunchDownload.checkSignedResources(Unknown Source)
                at com.sun.javaws.Launcher.prepareLaunchFile(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 above error is usually followed with:

java.io.IOException: Server returned HTTP response code: 500 for URL: http://starteamlg:19120/webstart/mtc/plugins/com.borland.hermes_8.9.0.jar
               at sun.reflect.GeneratedConstructorAccessor2.newInstance(Unknown Source)
               at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
               at java.lang.reflect.Constructor.newInstance(Unknown Source)
               at sun.net.www.protocol.http.HttpURLConnection$6.run(Unknown Source)
               at java.security.AccessController.doPrivileged(Native Method)
               at sun.net.www.protocol.http.HttpURLConnection.getChainedException(Unknown Source)
               at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
               at com.sun.deploy.net.BasicHttpRequest.doRequest(Unknown Source)
               at com.sun.deploy.net.BasicHttpRequest.doRequest(Unknown Source)
               at com.sun.deploy.net.BasicHttpRequest.doGetRequest(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.javaws.LaunchDownload.downloadJarFiles(Unknown Source)
               at com.sun.javaws.LaunchDownload.downloadEagerorAll(Unknown Source)
               at com.sun.javaws.Launcher.downloadResources(Unknown Source)
               at com.sun.javaws.Launcher.prepareLaunchFile(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)
Caused by: java.io.IOException: Server returned HTTP response code: 500 for URL: http://starteamlg:19120/webstart/mtc/plugins/com.borland.hermes_8.9.0.jar 
               at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
               at java.net.HttpURLConnection.getResponseCode(Unknown Source)
               ... 18 more

The exception is a known bug in an outdated JRE on the client machine(s). There are serveral JRE versions that are known to cause problems with Webstart, e.g. JRE 1.6u7 and 1.6u14.  In an updated JRE from these versions (for example, from version 1.6u29) Webstart should work again.

To resolved the issue, you must clean the browser cache and the Java Webstart cache (execute "javaws -uninstall") on all client machine(s) that you wish to install the Manual Testing Client Webstart.

Perform the following steps on all client machine(s) that you wish to install the Manual Testing Client:
1)  Clean the browser cache
2)  Clean the Java Webstart cache using the steps below:
          a) Load the Java Control Panel, Start | Control Panel | Java
          b) On the 'General' tab, select the 'Settings' button under the 'Temporary Internet Files'
          c) Then click 'Delete Files...' on the Temporary Files Dialog
          d) Agree to delete all Applications, Applets and log/trace files
3)   Execute 'javaws -uninstall' from the command prompt to uninstall the current java version on the client machine
4)   Install JRE 1.6 update 29 (Java SE 6 Update 29) or later from Java SE Downloads.

Note: Any of the JRE 1.6 versions should work but do not use JRe 1.6u7 or 1.6u14