Hi Mark,
I checked support tickets and only found one instance that may be related to your issue. Just in case you haven't seen them, the server requirements for Kentico installs are defined here:
https://docs.kentico.com/display/K82/Server+and+hosting+requirements
Most notably:
For the Kentico Installer to work correctly with your IIS, check that the following features are installed on your computer:
On Windows 7: ASP.NET 4.0 or 4.5, .NET Extensibility, ISAPI Extensions, ISAPI Filters and Static Content
On Windows 8: ASP.NET 4.5, .NET Extensibility 4.5, ISAPI Extensions, ISAPI Filters and Static Content
I know your installation is on Win 2012 R2, however, can you try enabling those settings on you VM and see if ti resolves your issue.