I tried to setup a nuget.server and created an empty ASP.NET 4.5.2 Project in VS2015. Then I added the nuget.server package. The added code won't compile because of various errors. Some usings are non exitent ( Nuget.Server.* ) and several types are missing.
I would have expected that it does compile out of the box.
This is a duplicate of issue #3257.
There is a bug in 2.12.2 where the package is incorrectly considered compatible with less than .NET 4.6. There are two workarounds until the next version of NuGet.Server is released.