You are probably here because you are not able to get a Java application to run.
You may see complaints that your Java is out of date.
You might see a black screen with an error message in the corner.
If so, try the following:

• Update Java
• Go into your Java Control Panel (in Windows from the Windows Control Panel)
• Go to the Security tab
• Click Edit Site List
• Click Add
• Copy/type in the resulting blank box: http://www.umass.edu
• Press OK

(If you have any other advice that would work better than the above, please let me know)