Hi, I am trying to use GLPK in my Java program. I want to invoke the solver on pressing a button on the frame. But every time I press the button all I see is NullPointerException. When I close the frame that time GLPK is invoked and send messages on the console of loading the model. It feels like the GlpkSolver is invoked after the calling program is terminated. Can anyone help me solving this issue.