When trying to compile a solution, I get the following build error:
Error MSB3644 The reference assemblies for framework \".NETFramework,Version=v4.
I was getting the exact same error when building except it was for ".NETFramework,Version=v4.7.1".
I downloaded the Developer pack for 4.7.1 from here: https://www.microsoft.com/en-us/download/confirmation.aspx?id=56119
The pack installed these programs on the target machine (my build server).
When I tried building again, I didn't get the error anymore and the build succeeded.