Autocomplete stops working when a .cs file and .csx file is in the same workspace

[SimHoZebs]

dotnet --info output:

.NET Core SDK (reflecting any global.json):
 Version:   3.1.401     
 Commit:    5b6f5e5005  

Runtime Environment:    
 OS Name:     Windows   
 OS Version:  10.0.18363
 OS Platform: Windows   
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\3.1.401\

Host (useful for support):
  Version: 3.1.7
  Commit:  fcfdef8d6b

.NET Core SDKs installed:
  3.1.202 [C:\Program Files\dotnet\sdk]
  3.1.302 [C:\Program Files\dotnet\sdk]
  3.1.401 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.App 3.1.4 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.7 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 3.1.4 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.7 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 3.1.4 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 3.1.6 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 3.1.7 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

VS Code version: 1.48.0
C# Extension version: 1.23.0

OmniSharp log

Starting OmniSharp server at 8/18/2020, 9:21:09 PM
    Target: c:\Users\UserName\FolderName\cs-scripts

OmniSharp server started.
    Path: c:\Users\UserName\.vscode\extensions\ms-dotnettools.csharp-1.23.0\.omnisharp\1.36.2-beta.22\OmniSharp.exe
    PID: 22572

[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 16.8.0 - "c:\Users\UserName\.vscode\extensions\ms-dotnettools.csharp-1.23.0\.omnisharp\1.36.2-beta.22\.msbuild\Current\Bin"
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        MSBUILD_EXE_PATH environment variable set to 'c:\Users\UserName\.vscode\extensions\ms-dotnettools.csharp-1.23.0\.omnisharp\1.36.2-beta.22\.msbuild\Current\Bin\MSBuild.exe'
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        Registered MSBuild instance: StandAlone 16.8.0 - "c:\Users\UserName\.vscode\extensions\ms-dotnettools.csharp-1.23.0\.omnisharp\1.36.2-beta.22\.msbuild\Current\Bin"
            CscToolExe = csc.exe
            CscToolPath = c:\Users\UserName\.vscode\extensions\ms-dotnettools.csharp-1.23.0\.omnisharp\1.36.2-beta.22\.msbuild\Current\Bin\Roslyn
            MSBuildExtensionsPath = c:\Users\UserName\.vscode\extensions\ms-dotnettools.csharp-1.23.0\.omnisharp\1.36.2-beta.22\.msbuild
            MSBuildToolsPath = c:\Users\UserName\.vscode\extensions\ms-dotnettools.csharp-1.23.0\.omnisharp\1.36.2-beta.22\.msbuild\Current\Bin
[info]: OmniSharp.Cake.CakeProjectSystem
        Detecting Cake files in 'c:\Users\UserName\FolderName\cs-scripts'.
[info]: OmniSharp.Cake.CakeProjectSystem
        Could not find any Cake files
[info]: OmniSharp.MSBuild.ProjectSystem
        No solution files found in 'c:\Users\UserName\FolderName\cs-scripts'
[info]: OmniSharp.Script.ScriptProjectSystem
        Detecting CSX files in 'c:\Users\UserName\FolderName\cs-scripts'.
[info]: OmniSharp.Script.ScriptProjectSystem
        Found 1 CSX files.
[info]: OmniSharp.Script.ScriptContextProvider
        Searching for compilation dependencies with the fallback framework of 'net461'.
[fail]: OmniSharp.Script.ScriptContextProvider
        Failed to resolve compilation dependencies
[info]: OmniSharp.Script.ScriptContextProvider
        Unable to find dependency context for CSX files. Will default to non-context usage (Desktop CLR scripts).
[info]: OmniSharp.Script.ScriptProjectSystem
        Added CSX project 'c:\Users\UserName\FolderName\cs-scripts\run.csx' to the workspace.
[info]: OmniSharp.WorkspaceInitializer
        Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.CSharpFormattingWorkspaceOptionsProvider, Order: 0
[info]: OmniSharp.WorkspaceInitializer
        Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.RenameWorkspaceOptionsProvider, Order: 100
[info]: OmniSharp.WorkspaceInitializer
        Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.ImplementTypeWorkspaceOptionsProvider, Order: 110
[info]: OmniSharp.WorkspaceInitializer
        Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.BlockStructureWorkspaceOptionsProvider, Order: 140
[info]: OmniSharp.WorkspaceInitializer
        Configuration finished.
[info]: OmniSharp.Stdio.Host
        Omnisharp server running using Stdio at location 'c:\Users\UserName\FolderName\cs-scripts' on host 18377.

Steps to reproduce

1. Launch vs-code with a folder/workspace containing a .cs file and .csx file. OmniSharp autocomplete stops working as expected.
   or
2. Launch vs-code with a folder/workspace containing a .csx/.cs file. Autocomplete works as expected.
3. Create a .cs/.csx file. OmniSharp autocomplete stops working as expected.

Expected behavior

OmniSharp autocomplete works in all mentioned situation.

Actual behavior

OmniSharp autocomplete stops working when a .cs file and .csx file is in the same directory.
Autocomplete starts working as expected if one of the file types are removed from directory.

[alaconda]

@YusukZebs I am having a similar issue #3988.

I was able workaround it by setting omnisharp.enableMsBuildLoadProjectsOnDemand = true in vscode settings.

You will still see a "Warning notification" saying that the project was not loaded properly, but the intellisense/autocomplete will start working and everything will compile properly.

Hope this workaround works for you as well.

[SimHoZebs]

@alaconda, thank you, but the workaround did not work. I don't think your issue is similar, because your project doesn't have a .csx file.

[SimHoZebs]

I found the solution. In VSCode terminal, run dotnet new console. Type dotnet build and restart VSCode if needed.

This is apparently required in C# dev env in VSCode but I was not aware, haha.