"The framework 'Microsoft.AspNetCore.App', version '3.1.0' was not found."

[simendsjo]

Looking at the published nuget package, this seems to be correct as I only see netcoreapp2.2 at nuget: https://www.nuget.org/packages/Microsoft.AspNetCore.App

The documentation, https://fsbolero.io/docs/, states that "version 3.0.0 or newer" is required. (EDIT: I'm trying 3.1.100)
Looking at the generated references, it includes a lot of preview stuff.

Does the project work atm? Anything I'm missing from the documentation?

[Tarmil]

I only see netcoreapp2.2 at nuget: https://www.nuget.org/packages/Microsoft.AspNetCore.App

This is because starting with version 3, the core App packages are not distributed via NuGet anymore, but built-in with the SDK. So if you have installed the 3.1.100 SDK, then you shouldn't have such issues. Do you maybe have a global.json file that points to an older SDK?

The documentation is outdated, sorry about that, I'll fix it quickly.

[simendsjo]

$ dotnet --version
3.1.100

$ dotnet new bolero-app -o MyApp
The template "Bolero Hosted Application" was created successfully.

$ cd MyApp
$ dotnet --version
3.1.100

$ dotnet run -p src/MyApp.Server/
It was not possible to find any compatible framework version
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&framework_version=3.1.0&arch=x64&rid=manjaro-x64

MyApp.Server.fsproj includes

  <ItemGroup>
    <ProjectReference Include="..\MyApp.Client\MyApp.Client.fsproj" />
    <PackageReference Include="Bolero.Server" Version="0.11.22-preview31" />
    <PackageReference Include="Bolero.HotReload.Server" Version="0.11.5-preview31" />
    <PackageReference Include="Microsoft.AspNetCore.Blazor.Server" Version="3.1-preview4.19579.2" />
    <PackageReference Include="Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation" Version="3.1" />
  </ItemGroup>

[Tarmil]

I just successfully ran the same sequence of commands with version 3.1.101 on both Windows and Ubuntu. What system are you on? Can you try to upgrade to 3.1.101?

[simendsjo]

Just tried 3.1.101, and I get the same behavior. This is on Manjaro, but I installed 3.1.101 from Arch AUR. I've experimented a bit with paket and removing some restrictions, but I'm unable to get it building.

[Tarmil]

What output do you get for dotnet --info? If you don't see a Microsoft.AspNetCore.App 3.1.* under ".NET Core runtimes installed", then I'm guessing it's not looking at the right place. In this case the fix would be to point the DOTNET_ROOT environment variable to wherever the AUR package installed dotnet. It seems to be /usr/share/dotnet: I see that the AUR archive contains a script that does that.

[simendsjo]

.NET Core SDK (reflecting any global.json):
 Version:   3.1.101
 Commit:    b377529961

Runtime Environment:
 OS Name:     manjaro
 OS Version:  
 OS Platform: Linux
 RID:         linux-x64
 Base Path:   /usr/share/dotnet/sdk/3.1.101/

Host (useful for support):
  Version: 3.1.1
  Commit:  a1388f194c

.NET Core SDKs installed:
  3.1.101 [/usr/share/dotnet/sdk]

.NET Core runtimes installed:
  Microsoft.NETCore.App 3.1.1 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

To install additional .NET Core runtimes or SDKs:
  https://aka.ms/dotnet-download

DOTNET_ROOT wasn't set for 3.1.101, but it doesn't seem to make any difference.

$ DOTNET_ROOT=/usr/share/dotnet dotnet run -p src/MyApp4.Server/ -v m
  Restore completed in 60.48 ms for /home/simendsjo/code/tmp/MyApp4/src/MyApp4.Server/MyApp4.Server.fsproj.
  Restore completed in 60.49 ms for /home/simendsjo/code/tmp/MyApp4/src/MyApp4.Client/MyApp4.Client.fsproj.
  MyApp4.Client -> /home/simendsjo/code/tmp/MyApp4/src/MyApp4.Client/bin/Debug/netstandard2.1/MyApp4.Client.dll
  MyApp4.Server -> /home/simendsjo/code/tmp/MyApp4/src/MyApp4.Server/bin/Debug/netcoreapp3.1/MyApp4.Server.dll
It was not possible to find any compatible framework version
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&framework_version=3.1.0&arch=x64&rid=manjaro-x64

Am I supposed to have a Microsoft.AspNetCore.App.dll? Who is referencing this? I'm new to dotnet core :/

I have a lot of dlls like the following: /usr/share/dotnet/packs/Microsoft.AspNetCore.App.Ref/3.1.0/ref/netcoreapp3.1/Microsoft.AspNetCore.dll
But no Microsoft.AspNetCore.App.dll.

While there are lots of preview versions in the project files, this one is just pinning 3.1: <PackageReference Include="Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation" Version="3.1" />. I also notice that the latest prerelease version for this package is 3.1.0-preview3.19555.2, but the other prerelease versions references is 3.1-preview4.19579.2.

[Tarmil]

Under .NET Core runtimes, there's Microsoft.NETCore.App, but not Microsoft.AspNetCore.App. I think that's the issue. There must be a separate AUR package to install for ASP.NET Core.

[simendsjo]

Under .NET Core runtimes, there's Microsoft.NETCore.App, but not Microsoft.AspNetCore.App. I think that's the issue. There must be a separate AUR package to install for ASP.NET Core.

Ah, thanks! I'm a bit blind it seems, and didn't notice the "Asp" difference in the runtime part. Sorry to steal your time with such a silly user error.

[Perustaja]

Know this is old but in-case anyone stumbled upon this, the package is aspnet-runtime in the Community repo currently.

[IvanArantes]

Know this is old but in-case anyone stumbled upon this, the package is aspnet-runtime in the Community repo currently.

Thank you very much! And also Tarmil for noticing the problem. I was stucked in this too..

[Neroli-realy]

Know this is old but in-case anyone stumbled upon this, the package is aspnet-runtime in the Community repo currently.

thanks i was stuck at this error too.. same OS.

[Jvaldez10]

Thank you, and solve problem in ARCH LINUX sudo pacman -S aspnet-runtime

[eramax]

Thanks guys, I had to install aspnet-runtime package to enable my asp.net app to run

https://aur.archlinux.org/packages/aspnet-runtime-bin

Regards