This is not an error. Sounds like the program is calling exit, abort, or is simply done with whatever it does. Since I'm not familiar with 'qualnet', I can't provide a solution.
You can try stepping through the program or setting breakpoints in various places to track the progress of the program and see where/why it is exiting. Alternatively, you can ask someone who is familiar with the program for help.
Patrick Nelson - Developer - Visual Studio Debugger Team