title: OmniSharp.MSBuild.ProjectManager Attempted to update project that is not loaded:
body: <p>I started to develop Asp.net Core web API with the VS code. But when I typing the code Intellisense/Suggestions not working properly. I saw in some resource on the internet while they are typing <code>using Microsoft.</code>, 
   <strong><code>EntityFrameworkCore</code></strong> showing as a suggestion. But In my case, it's not showing. In the <code>OmniSharp</code> log showing following error to me.</p>
  
  <pre><code>Starting OmniSharp server at 4/5/2019, 3:37:16 PM
      Target: c:\Dotnet Core\NgWebApi
  
  OmniSharp server started.
      Path: C:\Users\Acer\.vscode\extensions\ms-vscode.csharp-1.18.0\.omnisharp\1.32.11\OmniSharp.exe
      PID: 13684
  
  [info]: OmniSharp.Stdio.Host
          Starting OmniSharp on Windows 6.2.9200.0 (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\Acer\.vscode\extensions\ms-vscode.csharp-1.18.0\.omnisharp\1.32.11\msbuild\15.0\Bin"
  [info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
          MSBUILD_EXE_PATH environment variable set to 'C:\Users\Acer\.vscode\extensions\ms-vscode.csharp-1.18.0\.omnisharp\1.32.11\msbuild\15.0\Bin\MSBuild.exe'
  [info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
          Registered MSBuild instance: StandAlone 15.0 - "C:\Users\Acer\.vscode\extensions\ms-vscode.csharp-1.18.0\.omnisharp\1.32.11\msbuild\15.0\Bin"
              CscToolExe = csc.exe
              CscToolPath = C:\Users\Acer\.vscode\extensions\ms-vscode.csharp-1.18.0\.omnisharp\1.32.11\msbuild\15.0\Bin\Roslyn
              MSBuildExtensionsPath = C:\Users\Acer\.vscode\extensions\ms-vscode.csharp-1.18.0\.omnisharp\1.32.11\msbuild
              MSBuildToolsPath = C:\Users\Acer\.vscode\extensions\ms-vscode.csharp-1.18.0\.omnisharp\1.32.11\msbuild\15.0\Bin
  [info]: OmniSharp.Cake.CakeProjectSystem
          Detecting Cake files in 'c:\Dotnet Core\NgWebApi'.
  [info]: OmniSharp.Cake.CakeProjectSystem
          Could not find any Cake files
  [info]: OmniSharp.WorkspaceInitializer
          Project system 'OmniSharp.DotNet.DotNetProjectSystem' is disabled in the configuration.
  [info]: OmniSharp.MSBuild.ProjectSystem
          No solution files found in 'c:\Dotnet Core\NgWebApi'
  [info]: OmniSharp.MSBuild.ProjectManager
          Queue project update for 'c:\Dotnet Core\NgWebApi\NgWebApi.csproj'
  [info]: OmniSharp.Script.ScriptProjectSystem
          Detecting CSX files in 'c:\Dotnet Core\NgWebApi'.
  [info]: OmniSharp.Script.ScriptProjectSystem
          Could not find any CSX files
  [info]: OmniSharp.WorkspaceInitializer
          Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.CSharpWorkspaceOptionsProvider
  [info]: OmniSharp.MSBuild.ProjectManager
          Loading project: c:\Dotnet Core\NgWebApi\NgWebApi.csproj
  [info]: OmniSharp.WorkspaceInitializer
          Configuration finished.
  [info]: OmniSharp.Stdio.Host
          Omnisharp server running using Stdio at location 'c:\Dotnet Core\NgWebApi' on host 17188.
  [warn]: OmniSharp.MSBuild.ProjectManager
          Failed to load project file 'c:\Dotnet Core\NgWebApi\NgWebApi.csproj'.
  c:\Dotnet Core\NgWebApi\NgWebApi.csproj(1,1)
  Microsoft.Build.Exceptions.InvalidProjectFileException: The SDK 'Microsoft.NET.Sdk.Web' specified could not be found.  c:\Dotnet Core\NgWebApi\NgWebApi.csproj
     at Microsoft.Build.Shared.ProjectErrorUtilities.ThrowInvalidProject(String errorSubCategoryResourceName, IElementLocation elementLocation, String resourceName, Object[] args)
     at Microsoft.Build.Evaluation.Evaluator`4.ExpandAndLoadImportsFromUnescapedImportExpressionConditioned(String directoryOfImportingFile, ProjectImportElement importElement, List`1&amp; projects, Boolean throwOnFileNotExistsError)
     at Microsoft.Build.Evaluation.Evaluator`4.ExpandAndLoadImports(String directoryOfImportingFile, ProjectImportElement importElement)
     at Microsoft.Build.Evaluation.Evaluator`4.EvaluateImportElement(String directoryOfImportingFile, ProjectImportElement importElement)
     at Microsoft.Build.Evaluation.Evaluator`4.PerformDepthFirstPass(ProjectRootElement currentProjectOrImport)
     at Microsoft.Build.Evaluation.Evaluator`4.Evaluate(ILoggingService loggingService, BuildEventContext buildEventContext)
     at Microsoft.Build.Evaluation.Project.Reevaluate(ILoggingService loggingServiceForEvaluation, ProjectLoadSettings loadSettings)
     at Microsoft.Build.Evaluation.Project.ReevaluateIfNecessary(ILoggingService loggingServiceForEvaluation, ProjectLoadSettings loadSettings)
     at Microsoft.Build.Evaluation.Project.Initialize(IDictionary`2 globalProperties, String toolsVersion, String subToolsetVersion, ProjectLoadSettings loadSettings)
     at Microsoft.Build.Evaluation.Project..ctor(String projectFile, IDictionary`2 globalProperties, String toolsVersion, String subToolsetVersion, ProjectCollection projectCollection, ProjectLoadSettings loadSettings)
     at Microsoft.Build.Evaluation.ProjectCollection.LoadProject(String fileName, IDictionary`2 globalProperties, String toolsVersion)
     at OmniSharp.MSBuild.ProjectLoader.EvaluateProjectFileCore(String filePath)
     at OmniSharp.MSBuild.ProjectLoader.BuildProject(String filePath)
     at OmniSharp.MSBuild.ProjectFile.ProjectFileInfo.Load(String filePath, ProjectLoader loader)
     at OmniSharp.MSBuild.ProjectManager.LoadOrReloadProject(String projectFilePath, Func`1 loader)
  
  [fail]: OmniSharp.MSBuild.ProjectManager
          Attempted to update project that is not loaded: c:\Dotnet Core\NgWebApi\NgWebApi.csproj
  </code></pre>
  
  <p>I re-installed the VS Code and <code>C#</code> , <code>C# Extention</code> to solve this problem, but it's still occurring. I think the reason was to not showing Intellisense/Suggestions the project is not properly loaded. Can anyone tell me how to avoid this error and how to solve Intellisense/Suggestions not showing the issue.</p>