title: Mac OS does not open TopCoder Arena to open
body: <p>I'm running Mac OX 10.7.4 with the latest version of Java. I wanted to access TopCoder's Competition Arena, so I downloaded the .jnlp and tried to open it. However, I keep getting an error saying that the application is unsigned. I've attached screenshots of the error and the details thereof. Does anyone know how to fix this? </p>
  
  <p><img src="https://i.stack.imgur.com/u6qCw.png" alt="enter image description here">
  <img src="https://i.stack.imgur.com/z3s4L.png" alt="enter image description here"></p>