title: Docker - The framework microsoft.AspNetCore.App, version '3.1'0 was not found on build
body: <p>I'm attempting to learn about docker and how to containerize a .NET core Web app. I've been following the tutorial below and have made good progress except when I actually run my project.</p>
  
  <pre><code>https://devblogs.microsoft.com/premier-developer/running-a-net-core-web-application-in-docker-container-using-docker-desktop-for-windows/
  </code></pre>
  
  <p>I built a .NET Core app in visual studio and am using .NET Core 3.1 and I (think) have verified all the correct .NET core versions are installed, but docker seems to think that nothing is there. My project builds correctly but when I attempt to run it, it barks at me that no .NET frameworks were found.</p>
  
  <p>I'm new to docker and .NET core so I could definitely be missing something obvious so let me know if you have any suggestions! Thanks!</p>
  
  <p>dotnet --info</p>
  
  <pre><code>.NET Core SDK (reflecting any global.json):
   Version:   3.1.101
   Commit:    b377529961
  
  Runtime Environment:
   OS Name:     Windows
   OS Version:  10.0.17763
   OS Platform: Windows
   RID:         win10-x64
   Base Path:   C:\Program Files\dotnet\sdk\3.1.101\
  
  Host (useful for support):
    Version: 3.1.1
    Commit:  a1388f194c
  
  .NET Core SDKs installed:
    3.0.102 [C:\Program Files\dotnet\sdk]
    3.1.101 [C:\Program Files\dotnet\sdk]
  
  .NET Core runtimes installed:
    Microsoft.AspNetCore.All 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
    Microsoft.AspNetCore.App 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
    Microsoft.AspNetCore.App 3.0.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
    Microsoft.AspNetCore.App 3.1.1 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
    Microsoft.NETCore.App 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
    Microsoft.NETCore.App 3.0.2 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
    Microsoft.NETCore.App 3.1.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
    Microsoft.NETCore.App 3.1.1 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
    Microsoft.WindowsDesktop.App 3.0.2 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
    Microsoft.WindowsDesktop.App 3.1.1 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  
  To install additional .NET Core runtimes or SDKs:
    https://aka.ms/dotnet-download
  </code></pre>
  
  <p>docker pull mcr.microsoft.com/dotnet/core/runtime:3.1</p>
  
  <pre><code>3.1: Pulling from dotnet/core/runtime
  ee446884f7be: Already exists
  e60301a457d1: Already exists
  9aa45ac596a4: Already exists
  a0172a0e2f05: Already exists
  0e4e03cc72ce: Already exists
  d12a8fd361d3: Already exists
  Digest: sha256:1a314313bbfc550897fb760dc05c816f42e7f911c8bb8a4c9b5bde3cdad6ac76
  Status: Downloaded newer image for mcr.microsoft.com/dotnet/core/runtime:3.1
  mcr.microsoft.com/dotnet/core/runtime:3.1
  </code></pre>
  
  <p>docker build -t aspnetapp .
      Sending build context to Docker daemon  4.392MB</p>
  
  <pre><code>Step 1/10 : FROM mcr.microsoft.com/dotnet/core/sdk:3.1 AS build-env
   ---&gt; abe8d004f003
  Step 2/10 : WORKDIR /app
   ---&gt; Using cache
   ---&gt; baf04998e0f5
  Step 3/10 : COPY *.csproj ./
   ---&gt; Using cache
   ---&gt; 57d5b8ce9b8b
  Step 4/10 : RUN dotnet restore
   ---&gt; Using cache
   ---&gt; 3a78664422c1
  Step 5/10 : COPY . ./
   ---&gt; 7ad7515946be
  Step 6/10 : RUN dotnet publish -c Release -o out
   ---&gt; Running in 7b9fd1655346
  Microsoft (R) Build Engine version 16.4.0+e901037fe for .NET Core
  Copyright (C) Microsoft Corporation. All rights reserved.
  
    Restore completed in 41.18 ms for C:\app\aspnetapp.csproj.
    aspnetapp -&gt; C:\app\bin\Release\netcoreapp3.1\aspnetapp.dll
    aspnetapp -&gt; C:\app\bin\Release\netcoreapp3.1\aspnetapp.Views.dll
    aspnetapp -&gt; C:\app\out\
  Removing intermediate container 7b9fd1655346
   ---&gt; df9351064b25
  Step 7/10 : FROM mcr.microsoft.com/dotnet/core/runtime:3.1
   ---&gt; 96ec6546e277
  Step 8/10 : WORKDIR /app
   ---&gt; Running in 33e62d3940a5
  Removing intermediate container 33e62d3940a5
   ---&gt; 0fe4ecf63895
  Step 9/10 : COPY --from=build-env /app/out .
   ---&gt; fe8793b4a38d
  Step 10/10 : ENTRYPOINT ["dotnet", "aspnetapp.dll"]
   ---&gt; Running in a856a898d3f9
  Removing intermediate container a856a898d3f9
   ---&gt; 4802cf9997df
  Successfully built 4802cf9997df
  Successfully tagged aspnetapp:latest
  </code></pre>
  
  <p>dockerfile</p>
  
  <pre><code>FROM mcr.microsoft.com/dotnet/core/sdk:3.1 AS build-env
  
  WORKDIR /app
  
  # Copy csproj and restore as distinct layers
  
  COPY *.csproj ./
  
  RUN dotnet restore
  
  # Copy everything else and build
  
  COPY . ./
  
  RUN dotnet publish -c Release -o out
  
  # Build runtime image
  
  FROM mcr.microsoft.com/dotnet/core/runtime:3.1
  
  WORKDIR /app
  
  COPY --from=build-env /app/out .
  
  ENTRYPOINT ["dotnet", "aspnetapp.dll"]
  </code></pre>
  
  <p>docker error</p>
  
  <pre><code>docker run -p 8080:80 --name myapp aspnetapp
  docker : It was not possible to find any compatible framework version
  At line:1 char:1
  + docker run -p 8080:80 --name myapp aspnetapp
  + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      + CategoryInfo          : NotSpecified: (It was not poss...amework version:String) [], RemoteException
      + FullyQualifiedErrorId : NativeCommandError
  
  The framework 'Microsoft.AspNetCore.App', version '3.1.0' was not found.
    - No frameworks were found.
  You can resolve the problem by installing the specified framework and/or SDK.
  The specified framework can be found at:
    - https://aka.ms/dotnet-core-applaunch?framework=Microsoft.AspNetCore.App&amp;framework_version=3.1.0&amp;arch=x64&amp;rid=win10-x64
  </code></pre>
  
  <p>.csproj</p>
  
  <pre><code>&lt;Project Sdk="Microsoft.NET.Sdk.Web"&gt;
  
    &lt;PropertyGroup&gt;
      &lt;TargetFramework&gt;netcoreapp3.1&lt;/TargetFramework&gt;
    &lt;/PropertyGroup&gt;
  
  
  
  &lt;/Project&gt;
  </code></pre>
  
  <p>docker image -ls</p>
  
  <pre><code>REPOSITORY                              TAG                      IMAGE ID            CREATED             SIZE
  aspnetapp                               latest                   4802cf9997df        14 minutes ago      326MB
  &lt;none&gt;                                  &lt;none&gt;                   df9351064b25        14 minutes ago      748MB
  &lt;none&gt;                                  &lt;none&gt;                   05d5c7a53a75        18 minutes ago      748MB
  &lt;none&gt;                                  &lt;none&gt;                   cfc51668b9c9        40 minutes ago      400MB
  &lt;none&gt;                                  &lt;none&gt;                   c158d7286812        40 minutes ago      782MB
  &lt;none&gt;                                  &lt;none&gt;                   42135746c732        About an hour ago   400MB
  &lt;none&gt;                                  &lt;none&gt;                   a898ac91a635        About an hour ago   748MB
  &lt;none&gt;                                  &lt;none&gt;                   6c73f17b1c56        2 hours ago         1.66GB
  &lt;none&gt;                                  &lt;none&gt;                   bcdcd1874e78        2 hours ago         1.66GB
  myimage                                 latest                   1b4d8c7dffe4        3 hours ago         341MB
  mcr.microsoft.com/dotnet/core/samples   aspnetapp                17070fe9e96c        8 days ago          346MB
  mcr.microsoft.com/dotnet/core/samples   latest                   425e8480ff0f        8 days ago          322MB
  hello-world                             latest                   42514ac01c56        3 weeks ago         251MB
  mcr.microsoft.com/dotnet/core/sdk       3.1                      abe8d004f003        3 weeks ago         731MB
  microsoft/dotnet                        sdk                      bd7379c04097        3 weeks ago         1.66GB
  mcr.microsoft.com/dotnet/core/aspnet    3.1                      704413499629        3 weeks ago         341MB
  mcr.microsoft.com/dotnet/core/runtime   3.1                      96ec6546e277        3 weeks ago         321MB
  microsoft/dotnet                        2.1-aspnetcore-runtime   3c196369ffdc        3 weeks ago         395MB
  microsoft/dotnet                        aspnetcore-runtime       3c196369ffdc        3 weeks ago         395MB
  microsoft/dotnet                        3.0-aspnetcore-runtime   04b08b1edcee        11 months ago       437MB
  </code></pre>