Bluestacks is still in beta phase, which means that not all apps are compatible with it. Most likely, the app you're trying to run is having compatibility issues and because of that can't run normally. You can try contacting the developer using the email on the app page, but I doubt they will offer support for emulated environments. Download an older version of Bluestacks, but avoid updating it in case the application works.
Remove the current installation of Bluestacks before installing a new one and always reboot the PC after installation.