I have the same problem 100% of the time on 1 of my Win8.1/64 machines, about 50% of the time on my second 8.1/64 laptop, and zero percent of the time on my Win8.1/64 desktop #2.
Oddly they are all running the same version of Windows 8.1, meaning they are all patched to the same exact version and running the 64-bit version of the OS. I am running the latest version of Networx 5.3.1 64-bit.
I've also tried using Revo Uninstaller, with advanced options turned on, to remove all trace of the software -- then reinstalled it. Same exact problem.