We have the same request. Is there any help available? "java.awt.HeadlessException: No X11 DISPLAY variable was set, but this program performed an operation which requires it." X11 forwarding is in our terminal putty enabled, but there are still some bugs: "Exception in thread "main" java.lang.NoClassDefFoundError: Could not initialize class sun.awt.X11.XToolkit" Do we have to install x11 on the server (which is a overhead)?