Could not locate MSBuild instance to register with OmniSharp.

[DarkRRb]

OmniSharp Log:

D:\.code\CSharp\Demo>"C:\Users\<User>\Downloads\omnisharp.http-win-x64\OmniSharp.exe" -l Trace
trce: OmniSharp.Services.AssemblyLoader[0]
      Assembly loaded: OmniSharp.Cake
dbug: OmniSharp.CompositionHostBuilder[0]
      Loaded OmniSharp.Cake, Version=1.39.0.0, Culture=neutral, PublicKeyToken=7e5bf7b3b470b509
trce: OmniSharp.Services.AssemblyLoader[0]
      Assembly loaded: OmniSharp.DotNetTest
dbug: OmniSharp.CompositionHostBuilder[0]
      Loaded OmniSharp.DotNetTest, Version=1.39.0.0, Culture=neutral, PublicKeyToken=7e5bf7b3b470b509
trce: OmniSharp.Services.AssemblyLoader[0]
      Assembly loaded: OmniSharp.Host
dbug: OmniSharp.CompositionHostBuilder[0]
      Loaded OmniSharp.Host, Version=1.39.0.0, Culture=neutral, PublicKeyToken=7e5bf7b3b470b509
trce: OmniSharp.Services.AssemblyLoader[0]
      Assembly loaded: OmniSharp.MSBuild
dbug: OmniSharp.CompositionHostBuilder[0]
      Loaded OmniSharp.MSBuild, Version=1.39.0.0, Culture=neutral, PublicKeyToken=7e5bf7b3b470b509
trce: OmniSharp.Services.AssemblyLoader[0]
      Assembly loaded: OmniSharp.Roslyn
dbug: OmniSharp.CompositionHostBuilder[0]
      Loaded OmniSharp.Roslyn, Version=1.39.0.0, Culture=neutral, PublicKeyToken=7e5bf7b3b470b509
trce: OmniSharp.Services.AssemblyLoader[0]
      Assembly loaded: OmniSharp.Roslyn.CSharp
dbug: OmniSharp.CompositionHostBuilder[0]
      Loaded OmniSharp.Roslyn.CSharp, Version=1.39.0.0, Culture=neutral, PublicKeyToken=7e5bf7b3b470b509
trce: OmniSharp.Services.AssemblyLoader[0]
      Assembly loaded: OmniSharp.Script
dbug: OmniSharp.CompositionHostBuilder[0]
      Loaded OmniSharp.Script, Version=1.39.0.0, Culture=neutral, PublicKeyToken=7e5bf7b3b470b509
trce: OmniSharp.Services.AssemblyLoader[0]
      Assembly loaded: OmniSharp.Shared
dbug: OmniSharp.CompositionHostBuilder[0]
      Loaded OmniSharp.Shared, Version=1.39.0.0, Culture=neutral, PublicKeyToken=7e5bf7b3b470b509
info: OmniSharp.Services.DotNetCliService[0]
      Checking the 'DOTNET_ROOT' environment variable to find a .NET SDK
info: OmniSharp.Services.DotNetCliService[0]
      DotNetPath set to D:\Portable\dotnet\bin\dotnet
dbug: OmniSharp.CompositionHostBuilder[0]
      .NET SDK requires MSBuild instances version 16.3 or higher
info: OmniSharp.MSBuild.Discovery.MSBuildLocator[0]
      Located 0 MSBuild instance(s)
Could not locate MSBuild instance to register with OmniSharp.

I installed DotNet using the tutorial, I also configured the DOTNET_ROOT environment variable

dotnet --info

D:\.code\CSharp\Demo>dotnet --info
.NET SDK:
 Version:           8.0.303
 Commit:            29ab8e3268
 Workload version:  8.0.300-manifests.c915c39d
 MSBuild version:   17.10.4+10fbfbf2e

运行时环境:
 OS Name:     Windows
 OS Version:  10.0.19045
 OS Platform: Windows
 RID:         win-x64
 Base Path:   D:\Portable\dotnet\bin\sdk\8.0.303\

已安装 .NET 工作负载:
没有要显示的已安装工作负载。

Host:
  Version:      8.0.7
  Architecture: x64
  Commit:       2aade6beb0

.NET SDKs installed:
  8.0.303 [D:\Portable\dotnet\bin\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 8.0.7 [D:\Portable\dotnet\bin\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 8.0.7 [D:\Portable\dotnet\bin\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 8.0.7 [D:\Portable\dotnet\bin\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
  None

Environment variables:
  DOTNET_ROOT       [D:\Portable\dotnet\bin]

global.json file:
  Not found

Learn more:
  https://aka.ms/dotnet/info

Download .NET:
  https://aka.ms/dotnet/download

The above shows that I have an MSBuild 17.10.4+10fbfbf2e

But OnmiSharp cannot detect and use it

[Lexpeartha]

Experiencing possibly the same issue, although I get different error message:

OmniSharp.Extensions.JsonRpc.DefaultRequestInvoker: Failed to handle request initialize 0 - System.InvalidOperationException: Failed to find all versions of .NET Core MSBuild.

Here's what my dotnet --info gives me:

.NET SDK:
 Version:           8.0.401
 Commit:            811edcc344
 Workload version:  8.0.400-manifests.b6724b7a
 MSBuild version:   17.11.4+37eb419ad

Runtime Environment:
 OS Name:     vanilla
 OS Version:  2.0
 OS Platform: Linux
 RID:         linux-x64
 Base Path:   /usr/share/dotnet/sdk/8.0.401/

.NET workloads installed:
Configured to use loose manifests when installing new manifests.
There are no installed workloads to display.

Host:
  Version:      8.0.8
  Architecture: x64
  Commit:       08338fcaa5

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

.NET runtimes installed:
  Microsoft.AspNetCore.App 8.0.8 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 8.0.8 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
  None

Environment variables:
  Not set

global.json file:
  Not found

Learn more:
  https://aka.ms/dotnet/info

Download .NET:
  https://aka.ms/dotnet/download

Even tried overriding DOTNET_MSBUILD_SDK_RESOLVER_* env variables manually, but that didn't help.

[JoeRobich]

@CwkDark OmniSharp looks for the dotnet CLI to be available from the PATH.

@Lexpeartha Does the folder you are opening have a global.json? If so, what version of the SDK is it pinning?

[Lexpeartha]

@Lexpeartha Does the folder you are opening have a global.json? If so, what version of the SDK is it pinning?

No, I don't this it has. The only version I have, which would be 8.0.4 I believe.

[JoeRobich]

@Lexpeartha I found this issue comment that might help. microsoft/MSBuildLocator#302 (comment)

[DarkRRb]

@CwkDark OmniSharp looks for the dotnet CLI to be available from the PATH.

dotnet CLI is located in PATH

[JoeyGee]

I got the same issue. I simply downloaded the wrong release (omnisharp-win-x64). As soon as I got the right release (omnisharp-win-x64-net6.0) the msbuild instances for netcore were found.