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

The problem here is that Microsoft confused a whole lot of people with how they numbered their .NET Core SDKs.

In the original poster's message the path C:\Program Files\dotnet\sdk\2.1.100\ DOES NOT appear to represent the .NET Core 2.1 runtime (but you'd think it does).

I came across this post The current .NET SDK does not support targeting .NET Core 2.1 on developercommunity.visualstudio.com where a Microsoft support person explains the confusion:

"Thank you for your feedback! We have determined that this issue is not a bug. The first SDK with .NET Core 2.1 support is 2.1.300-preview1. We know the versioning is confusing which is why starting in 2.1.300, the major.minor versions of the SDK will now be aligned with the major.minor versions of the runtime as well."

So ... in order to get .NET Core 2.1 support for building via the SDK you need to install the SDK with version 2.1.300 at least (since 2.1.2 is NOT .NET Core 2.1) ... yeah, confusing. Thank you Microsoft for some lost time on this.

This happened to me after installing 2.2.100-preview3-009430 and then updating to Visual Studio 15.9.2.

I resolved by enabling the "Use previews of the .NET Core SDK" option.

Go to: Tools > Options > Projects and Solutions > .NET Core Check the "Use previews of the .NET Core SDK" box Restart Visual Studio and rebuild the solution.

VS Preview Options

Installing .NET Core SDK 2.1.300-preview2 did the trick for me:

UPDATE: just in case, there is a newer version has been released recently. You can download the new .NET Core SDK for 2.2.0-preview1 (which includes ASP.NET 2.2.0-preview1) here.

See also this answer when you are getting error like this in general:

The current .NET SDK does not support targeting .NET Core 2.X

I resolved the problem. the cause was that i installed

aspnetcore-runtime-2.1.0-preview1-final-win-x64 and

.net core SDK 2.1.4-x64 versions.

The installation placed the sdk files in c:\Program Files\dotnet

but VS2017 32bit was looking for the sdk files in c:\Program Files(x86)\dotnet.

To resolve this i

installed the x86 version of the sdk and aspnetcore runtime,

set the MSBuildSDKsPath environmental variable to point to the new installation path.

deleted all obsolete sdks from control panel

The question VS2017 Update 3 'Microsoft.NET.Sdk.Web' could not be found helped in resolving this issue.

https://www.microsoft.com/net/download/visual-studio-sdks

You can download the SDK from the above site

check the SDK which is in your machine Path C:\Program Files\dotnet\sdk

Change or check the target framework in visual studio,

Right click on Startup Application or project => Application => Target Framework.

You can change the framework and build the solution and restore nugget packages.

https://i.stack.imgur.com/sCbIG.png

Same happened to me, but then for version 2.2 of .NET Core. I installed the latest version of .NET Core 2.2 SDK, which was 2.2.202 at that time. Visual studio allowed me to create a new project for Core 2.2, but it was showing the error:

"The current .NET SDK does not support targeting .NET Core 2.2. Either target .NET Core 2.1 or lower, or use a version of the .NET SDK that supports .NET Core 2.2."

The target framework for my project was empty and the dropdown didn't show 2.2.

After installing .NET Core SDK 2.2.103, the error was gone and the dropdown did show ".NET Core 2.2".

Check to make sure you don't have global.json file in your project root folder that forces your project to use .NET SDK 2.1 only.

If you have this global.json file, delete it, and then restart visual studio.

As embarrassing as it might sound, I spent almost an hour tinkering and I even downloaded several SDK version to force it to use 2.2

Stopping IIS for publishing solved the problem. But first I needed to install net core 2.1 SDK and update the Visual Studio.

I had the .Net Core SDK 2.1.4 installed and followed the other answers in this post without solving my problem. What finally did it for me was installing .Net Core SDK version 2.1.301, and uninstalling every other version. Seems like the SDK 2.1.4 cannot target .Net Core 2.1 but SDK 2.1.301 does the job.

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. "

I am using Rider, I had

The current .NET SDK does not support targeting .NET Core 2.2. Either target .NET Core 2.1 or lower, or use a version of the .NET SDK that supports .NET Core 2.2

I had:

$ dotnet --list-sdks
2.1.2 [C:\Program Files\dotnet\sdk]
2.1.202 [C:\Program Files\dotnet\sdk]
2.1.505 [C:\Program Files\dotnet\sdk]
2.1.602 [C:\Program Files\dotnet\sdk]
2.2.202 [C:\Program Files\dotnet\sdk]

I tried keeping only the latest sdk, and had:

Project 'WebApplication3' load failed: The SDK 'Microsoft.NET.Sdk.Web' specified could not be found..

So I removed everything and reinstalled 2.1.602. Made a new project from Rider. And it worked. Cannot say I understood how I solved it...

The issues for some peoples seems to be linked to global.json, see:
- https://docs.microsoft.com/fr-fr/aspnet/core/migration/21-to-22?view=aspnetcore-2.2&tabs=visual-studio
- https://docs.microsoft.com/fr-fr/dotnet/core/tools/global-json
- https://andrewlock.net/the-sdk-microsoft-net-sdk-web-specified-could-not-be-found/

Other things I did before (that did not seem to solve the issue but might have helped?): - Updating Rider from 2018.3.2 to 2018.3.4 (latest). - Installing Mono (was using the one from Unity when look into Rider build settings). - Tried to use custom MSBuild from Jetbrain (the one used for Linux) without success. - Installing everything related to .NET Core from VS installer. - Update VS community ot latest. - Reboot.

In Rider/Build, Execution, Deployement/Toolset and Build I now have:
Mono executable: C:\Program Files\Mono\bin\mono.exe
- NET Core CLI executable: C:\Program Files\dotnet\dotnet.exe
- Use MS Build version (Auto detected 16.0): C:\Program - Files\dotnet\sdk\2.1.602\MSBuild.dll

I started getting this error after I installed SDK 2.2.300. After reading this post and some other I downgrade it to SDK 2.2.1xx and the error went away. Note: I had to uninstall SDK 2.2.300 and restart after installing SDK 2.2.1xx.

I had this problem and I did a fresh install of VS2017. That fixed it!

Go to your pipeline. Click on Edit pipeline. Click on the Agent Specification dropdown. Change it to Windows 2019. Click Save And Queue.

And here you Go. It worked fine for me.

I had the same issue with Visual Studio 2017. Right click on the project and go to the properties. From there you can change the target framework. Choose appropriate framework and run your project. This solution was worked for me.

It looks like Microsoft are encouraging better coding practice for those early adopters of latest development software in Net Core 2.1 by removing the capability to use older software where bad habits prevail. Net Core 2.0 and the older versions are almost end of life so should not be being used at all. (https://blogs.msdn.microsoft.com/dotnet/2018/06/20/net-core-2-0-will-reach-end-of-life-on-september-1-2018/)

1) Microsoft have removed ServiceLocator since widely considered an anti-pattern resulting in difficult to understand code.

2) To improve MVC applications, the AccountController was removed from Authentication/Authorization to encourage use of Razor pages which implement the Single Responsibiity Principle.

It would not be considered best practice to circumvent these changes in order to increase perpetuation of software built to lower software engineering standards in the past.