One of our users has met this problem on Windows 8.1
If you have it then you can fix it by installing Visual C++ 2013 redistributables at the following link: https://www.microsoft.com/en-us/download/details.aspx?id=40784
This problem is generated by a wrong reference to this library.
It will be fixed with the upcoming release of CFDEMworkbench (June 2018) without the requirement to install additional redistributables.
Alessandro Sacilotto (Software development - DCS Computing GmbH)