How to fix a failure in upgrading from ASP.NET Core 1.0.x to ASP.NET Core 1.1

Error I received

  1. The project has not been restored or restore failed – run dotnet restore

  2. The project does not list one of ‘win10-x64, win81-x64, win8-x64, win7-x64’ in the ‘runtimes’ section.

  3. You may be trying to publish a library, which is not supported. Use dotnet pack to distribute libraries.

Can not find runtime target for framework ‘.NETCoreApp,Version=v1.1’ compatible with one of the target runtimes: ‘win10-x64, win81-x64, win8-x64, win7-x64’.

How to fix it

Open your project.json and under “dependencies” change

"Microsoft.NETCore.App": "1.1.0",


"Microsoft.NETCore.App": { "version": "1.1.0", "type":  "platform" },

Then re-run your app.


How it happened

I’m still using Visual Studio 2015, but I have .NET Core 1.1 downloaded and installed and I wanted to upgrade to .NET Core 1.1 and update to all the latest ASP.NET Core 1.1 packages.

I went to File => New Project => ASP.NET Core Web Application, which proceeded to give me .NET Core 1.0.1, which was expected.  I followed the upgrade path, but I forgot to hit “Save” on my project.json in step 2, when I changed the values to .NET Core 1.1.0.  Therefore, it did not restore the .NET Core 1.1 NuGet package.

So when I went to the NuGet UI under Updates, .NET Core was an option to update, which I didn’t realize when I hit “Update All.”  Well that jacked with my project.json in this way…





NuGet removed my JSON nested object with just the version number.  What the “type”:”platform” does is it tells my project that it expects .NET Core will already be installed on the machine, therefore it will not bundle .NET Core with my app.

When “type” : “platform” is NOT specified, then it assumes I am bundling .NET Core WITH my app.  In that case, I need to specify the exact platforms that I’m targeting (i.e. Windows 10, Linux, Mac, etc.) in the “runtimes” section.  However, that “runtimes” section was not there previously, because I was targeting the platform.

This seems like it would be a bug with NuGet.  It should only update the Version, and not overwrite anything else.  Maybe this gets fixed during the switch to csproj coming soon.  I’m not going to file a bug at this point on GitHub, because I doubt they make the investment to fix this in project.json.