I couldn't reproduce your problem, but I might have done something different. Here's what I did step-by-step:
1) New VI
2) Drop RT Ping Controllers.vi on the diagram
3) Create controls for error in and system location
4) Create indicators for error out and controllers on subnet
5) Right-click on VI icon, choose "Show Connector"
6) Wire up the four terminals
7) Save VI and run it
This worked for me. Are these the steps you followed?