VOSPEC Troubleshooting

Here we list some of the most common environmental factors that may affect the proper functioning of VOSpec, or any other java VO application:

  • The Java Virtual Machine: Check that you have an up to date version of the Java virtual machine. It is not only the version that can affect the VOSpec functioning, but also the implementation used (Oracle provides one but there are a few others available). We recommend that you try a new installation of the latest version provided by Oracle: http://java.com/en/download/index.jsp

    To check the version of your Java virtual machine, type "java -version" in a command line, or go here:


  • Execution Method: There are three ways to execute VOSpec: Applet, WebStart and standalone ".jar" file. This is also the case for many other VO applications. The amount of memory provided for the applet version is directly limited by your browser. The amount of memory provided for the WebStart version is bigger but limited. And the amount of memory provided for the standalone jar can be directly set according to the resources of your machine:

    For the standalone jar, we recommend you run it with the following command: "java -jar VOSpec_6.5.jar -Xms512m -Xmx1024m" 


  • Network Problems: VOSpec requires HTTP under port 80, and port 8080 for some VO services. Some firewalls are set up to block one or both of these ports. Also, if the firewall is tracing the traffic, some of the messages that VO applications require might be identified as SQL injection attacks. If you are accessing VOSpec behind a firewall, check with your computer support services if either of these ports are blocked.

If none of the above solutions solved the problem you are having, please contact the VOSpec helpdesk.