Use Visual Studio 2017 with .Net Core SDK 2.0

Update:

There is now a VS 2017 15.3 preview that resolves this issue. Starting with VS 15.3, Visual Studio carries an MSBuild SDK resolver that determines which version of the CLI SDK a project would use (e.g. if a global.json sets the version) and uses it's MSBuild targets so new previews are picked up by VS.

Original:

You can modify your environment to get VS 2017 support for the unreleased 2.0 tooling by setting the MSBuildSdksPath as described in https://github.com/aspnet/Announcements/issues/231 so that VS picks up the build logic from the CLI.

The Visual Studio .NET Core tools were just released in March, yet the 2.0 preview you are using was released in April. https://blogs.msdn.microsoft.com/dotnet/2017/03/07/announcing-net-core-tools-1-0/ You'll need to wait for an update to the .NET Core Tools before you can use Visual Studio with .NET Core 2.0