So... the build error has nothing to do with whether I'm using VS2013 or not.
It had to do with the NuGet package - CodeDOM Providers for .NET Compiler Platform ("Roslyn").
I had to Uninstall and Reinstall that package in order for it to build properly.
Given that, even though I will be testing the code samples generated by VS2013 (i.e. not VS2015+), I would like to hear from anyone else out there who are successfully using the Automation SDK 6.7 built with VS2013 or pre-VS2015 ?
The "VMWare vSphere Automation SDKs Programming Guide" for 6.7, section "SDK Developer Setup", tells the user to find instructions for settings up a development environment in the README document for the SDK.
Viewing the README.md, under section "### Setting up build environment", you'll see the statement:
To build and run the samples, install Microsoft Visual Studio 2015 or higher.
In the end, I was able to build the SDK in VS 2013... and did execute some of the sample code successfully.
So I think this is just a "documentation" issue.
Yes, that was a document issue. I have also face the same issue and then I contacted to Geek Squad and they tell me about this problem with a proper solution. It was a nice experience and you can also contact them for future problems related to vSphere.