OmniSharp.MSBuild.ProjectLoader The "GetReferenceNearestTargetFrameworkTask" task was not found

Environment data dotnet --info output:

Пакет SDK для .NET Core (отражающий любой global.json):
 Version:   2.1.401
 Commit:    91b1c13032

Среда выполнения:
 OS Name:     Windows
 OS Version:  6.1.7601
 OS Platform: Windows
 RID:         win7-x64
 Base Path:   C:\Program Files\dotnet\sdk\2.1.401\

Host (useful for support):
  Version: 2.1.3
  Commit:  124038c13e

.NET Core SDKs installed:
  2.1.401 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.All 2.1.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.3 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]

VS Code version: C# Extension version:

Версия: 1.27.1 (system setup) Фиксация: 5944e81f3c46a3938a82c701f96d7a59b074cfdc Дата: 2018-09-06T09:21:10.934Z Electron: 2.0.7 Chrome: 61.0.3163.100 Node.js: 8.9.3 V8: 6.1.534.41 Архитектура: ia32

Steps to reproduce after the last update Omni Sharp stopped working log:

Starting OmniSharp server at 9/11/2018, 2:03:34 PM
    Target: c:\Project\Test\Test.sln

OmniSharp server started.
    Path: C:\Users\borr\.vscode\extensions\ms-vscode.csharp-1.16.0\.omnisharp\1.32.4\OmniSharp.exe
    PID: 6744

[info]: OmniSharp.Stdio.Host
        Starting OmniSharp on Windows 6.1.7601.65536 (x64)
[info]: OmniSharp.Services.DotNetCliService
        DotNetPath set to dotnet
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        Located 1 MSBuild instance(s)
            1: StandAlone 15.0 - "C:\Users\borr\.vscode\extensions\ms-vscode.csharp-1.16.0\.omnisharp\1.32.4\msbuild\15.0\Bin"
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        MSBUILD_EXE_PATH environment variable set to 'C:\Users\borr\.vscode\extensions\ms-vscode.csharp-1.16.0\.omnisharp\1.32.4\msbuild\15.0\Bin\MSBuild.exe'
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        Registered MSBuild instance: StandAlone 15.0 - "C:\Users\borr\.vscode\extensions\ms-vscode.csharp-1.16.0\.omnisharp\1.32.4\msbuild\15.0\Bin"
            CscToolExe = csc.exe
            CscToolPath = C:\Users\borr\.vscode\extensions\ms-vscode.csharp-1.16.0\.omnisharp\1.32.4\msbuild\15.0\Bin\Roslyn
            MSBuildExtensionsPath = C:\Users\borr\.vscode\extensions\ms-vscode.csharp-1.16.0\.omnisharp\1.32.4\msbuild
            MSBuildToolsPath = C:\Users\borr\.vscode\extensions\ms-vscode.csharp-1.16.0\.omnisharp\1.32.4\msbuild\15.0\Bin
[info]: OmniSharp.Cake.CakeProjectSystem
        Detecting Cake files in 'c:\Project\Test'.
[info]: OmniSharp.Cake.CakeProjectSystem
        Could not find any Cake files
[info]: OmniSharp.Stdio.Host
        Project system 'OmniSharp.DotNet.DotNetProjectSystem' is disabled in the configuration.
[info]: OmniSharp.MSBuild.ProjectSystem
        Detecting projects in 'c:\Project\Test\Test.sln'.
[info]: OmniSharp.MSBuild.ProjectManager
        Queue project update for 'c:\Project\Test\Assembly-CSharp.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
        Queue project update for 'c:\Project\Test\Assembly-CSharp-firstpass.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
        Queue project update for 'c:\Project\Test\Assembly-CSharp-Editor.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
        Queue project update for 'c:\Project\Test\Assembly-CSharp-Editor-firstpass.csproj'
[info]: OmniSharp.Script.ScriptProjectSystem
        Detecting CSX files in 'c:\Project\Test'.
[info]: OmniSharp.MSBuild.ProjectManager
        Loading project: c:\Project\Test\Assembly-CSharp.csproj
[info]: OmniSharp.Script.ScriptProjectSystem
        Could not find any CSX files
[info]: OmniSharp.Stdio.Host
        Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.CSharpWorkspaceOptionsProvider
[info]: OmniSharp.Stdio.Host
        Configuration finished.
[info]: OmniSharp.Stdio.Host
        Omnisharp server running using Stdio at location 'c:\Project\Test' on host 5136.
[fail]: OmniSharp.MSBuild.ProjectLoader
        The "GetReferenceNearestTargetFrameworkTask" task was not found. Check the following: 1.) The name of the task in the project file is the same as the name of the task class. 2.) The task class is "public" and implements the Microsoft.Build.Framework.ITask interface. 3.) The task is correctly declared with <UsingTask> in the project file, or in the *.tasks files located in the "C:\Users\borr\.vscode\extensions\ms-vscode.csharp-1.16.0\.omnisharp\1.32.4\msbuild\15.0\Bin" directory.
[warn]: OmniSharp.MSBuild.ProjectManager
        Failed to load project file 'c:\Project\Test\Assembly-CSharp.csproj'.
c:\Project\Test\Assembly-CSharp.csproj
C:\Users\borr\.vscode\extensions\ms-vscode.csharp-1.16.0\.omnisharp\1.32.4\msbuild\15.0\Bin\Microsoft.Common.CurrentVersion.targets(1657,5): Error: The "GetReferenceNearestTargetFrameworkTask" task was not found. Check the following: 1.) The name of the task in the project file is the same as the name of the task class. 2.) The task class is "public" and implements the Microsoft.Build.Framework.ITask interface. 3.) The task is correctly declared with <UsingTask> in the project file, or in the *.tasks files located in the "C:\Users\borr\.vscode\extensions\ms-vscode.csharp-1.16.0\.omnisharp\1.32.4\msbuild\15.0\Bin" directory.

[info]: OmniSharp.MSBuild.ProjectManager
        Loading project: c:\Project\Test\Assembly-CSharp-firstpass.csproj
[info]: OmniSharp.MSBuild.ProjectManager
        Successfully loaded project file 'c:\Project\Test\Assembly-CSharp-firstpass.csproj'.
[info]: OmniSharp.MSBuild.ProjectManager
        Adding project 'c:\Project\Test\Assembly-CSharp-firstpass.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
        Loading project: c:\Project\Test\Assembly-CSharp-Editor.csproj
[fail]: OmniSharp.MSBuild.ProjectLoader
        The "GetReferenceNearestTargetFrameworkTask" task was not found. Check the following: 1.) The name of the task in the project file is the same as the name of the task class. 2.) The task class is "public" and implements the Microsoft.Build.Framework.ITask interface. 3.) The task is correctly declared with <UsingTask> in the project file, or in the *.tasks files located in the "C:\Users\borr\.vscode\extensions\ms-vscode.csharp-1.16.0\.omnisharp\1.32.4\msbuild\15.0\Bin" directory.
[warn]: OmniSharp.MSBuild.ProjectManager
        Failed to load project file 'c:\Project\Test\Assembly-CSharp-Editor.csproj'.
c:\Project\Test\Assembly-CSharp-Editor.csproj
C:\Users\borr\.vscode\extensions\ms-vscode.csharp-1.16.0\.omnisharp\1.32.4\msbuild\15.0\Bin\Microsoft.Common.CurrentVersion.targets(1657,5): Error: The "GetReferenceNearestTargetFrameworkTask" task was not found. Check the following: 1.) The name of the task in the project file is the same as the name of the task class. 2.) The task class is "public" and implements the Microsoft.Build.Framework.ITask interface. 3.) The task is correctly declared with <UsingTask> in the project file, or in the *.tasks files located in the "C:\Users\borr\.vscode\extensions\ms-vscode.csharp-1.16.0\.omnisharp\1.32.4\msbuild\15.0\Bin" directory.

[info]: OmniSharp.MSBuild.ProjectManager
        Loading project: c:\Project\Test\Assembly-CSharp-Editor-firstpass.csproj
[fail]: OmniSharp.MSBuild.ProjectLoader
        The "GetReferenceNearestTargetFrameworkTask" task was not found. Check the following: 1.) The name of the task in the project file is the same as the name of the task class. 2.) The task class is "public" and implements the Microsoft.Build.Framework.ITask interface. 3.) The task is correctly declared with <UsingTask> in the project file, or in the *.tasks files located in the "C:\Users\borr\.vscode\extensions\ms-vscode.csharp-1.16.0\.omnisharp\1.32.4\msbuild\15.0\Bin" directory.
[warn]: OmniSharp.MSBuild.ProjectManager
        Failed to load project file 'c:\Project\Test\Assembly-CSharp-Editor-firstpass.csproj'.
c:\Project\Test\Assembly-CSharp-Editor-firstpass.csproj
C:\Users\borr\.vscode\extensions\ms-vscode.csharp-1.16.0\.omnisharp\1.32.4\msbuild\15.0\Bin\Microsoft.Common.CurrentVersion.targets(1657,5): Error: The "GetReferenceNearestTargetFrameworkTask" task was not found. Check the following: 1.) The name of the task in the project file is the same as the name of the task class. 2.) The task class is "public" and implements the Microsoft.Build.Framework.ITask interface. 3.) The task is correctly declared with <UsingTask> in the project file, or in the *.tasks files located in the "C:\Users\borr\.vscode\extensions\ms-vscode.csharp-1.16.0\.omnisharp\1.32.4\msbuild\15.0\Bin" directory.

[fail]: OmniSharp.MSBuild.ProjectManager
        Attemped to update project that is not loaded: c:\Project\Test\Assembly-CSharp.csproj
[info]: OmniSharp.MSBuild.ProjectManager
        Update project: Assembly-CSharp-firstpass
[fail]: OmniSharp.MSBuild.ProjectManager
        Attemped to update project that is not loaded: c:\Project\Test\Assembly-CSharp-Editor.csproj
[fail]: OmniSharp.MSBuild.ProjectManager
        Attemped to update project that is not loaded: c:\Project\Test\Assembly-CSharp-Editor-firstpass.csproj

OS Windows 7 SP1, Unity 2018.1 project

[boris-741]

fix with 1.16.1

[vlab22]

After update everything, solved with solution below. https://developercommunity.visualstudio.com/content/problem/160494/msbuild-broken-getreferencenearesttargetframeworkt.html