The current .NET SDK does not support targeting .NET Core 2.1. Either target .NET Core 2.0 or lower, or use a .NET SDK that supports .NET Core 2.1

Question

have tried upgrading to the professional version of visual studio 2017 v 15.6.0 (Preview 7.0)

and installed aspnetcore-runtime-2.1.0-preview1-final-win-x64 and .net

Answer 1

I also solved the problem in this way:

Check versions on dotnet sdk available

C:\Users\me>dotnet --list-sdks

 ##2.1.202 [C:\Program Files\dotnet\sdk]
 ##2.1.505 [C:\Program Files\dotnet\sdk]
 ##2.1.508 [C:\Program Files\dotnet\sdk]
 ##2.1.509 [C:\Program Files\dotnet\sdk]
 ##2.1.511 [C:\Program Files\dotnet\sdk]
 ##2.1.514 [C:\Program Files\dotnet\sdk]
 ##2.1.801 [C:\Program Files\dotnet\sdk]

I tested my build on all of those versions and it does not work until I uninstalled all of the above from Programs and Features. Then download from the latest:

https://dotnet.microsoft.com/download/dotnet-core/thank-you/sdk-3.1.300-windows-x64-installer

This worked. Dont waste time like i did just install latest version of dotnet sdk and you good to go. "