I am amazed it even ever works... The following code will get you into trouble:
Instead of Close you should set the state (with a property node) to hidden, and after running the sub-vi set the FP to Standard. Instead of opening a reference with the path node you should use 'this vi' in the application control palette. The reason your exe fails is quite simple, for a very short time there is no front panel open. Without any front panel open the executable will terminate itself.