This is an issue on Linux.  Both the installation script and startup script works fine without X11.  However, the shutdown script require X11.  There is no reason for this requirement and most production Linux boxes don't for X.  I had to manually kill the server.

Here is the output.

# ./ShutDownOpManager.sh

Exception in thread "main" java.awt.HeadlessException:

No X11 DISPLAY variable was set, but this program performed an operation which requires it.

        at java.awt.GraphicsEnvironment.checkHeadless(Unknown Source)

        at java.awt.Window.<init>(Unknown Source)

        at java.awt.Frame.<init>(Unknown Source)

        at java.awt.Frame.<init>(Unknown Source)

        at javax.swing.JFrame.<init>(Unknown Source)

        at com.adventnet.me.opmanager.tray.ShutDownUI.main(ShutDownUI.java:668)