In Unity + VSCode, Fixed vscode intellisense not working.

Summury Of Article

When I created a new Unity 2020.3 LTS + VSCode environment and started coding, I solved the problem that code completion (Intellisense) did not work in VSCode, so I will write down the solution.

My Enviroment

Software	Version
Unity	Unity2020.3 LTS
OS	Windows 10 Home
VSCode	1.63.2

Symptoms

I've already installed the following as an extension to VSCode, which is suitable for coding with Unity. The following are already installed.

Installed VSCode Extension

In this state, when I open the code from Unity, Intellisense (code completion, etc.) does not work.

For example, creating a new scripting file (cs file) in unity. In the void Start() method, type this.game and then Ctrl + Space. It should show this.gameObject as a candidate, but it doesn't.

Here's what happens when the candidate is displayed (ideally).

ideal

Fix

Open it as a project in VSCode properly from Unity. (It is assumed that opening VSCode from Unity is pre-associated.)

Open vscode project from Unity

Asset -> Open C# Project

The following error was displayed in the "Output" tab of VSCode.

errormessage

[warn]: OmniSharp.MSBuild.ProjectManager
        Failed to load project file 'c:\myunityproject\Assembly-CSharp.csproj'.
c:\myunityproject\Assembly-CSharp.csproj
c:\Users\amaji\.vscode\extensions\ms-dotnettools.csharp-1.23.17
  \.omnisharp\1.37.17\.msbuild\Current\Bin
  \Microsoft.Common.CurrentVersion.targets(1217,5):
    Error: The reference assemblies for .NETFramework,Version=v4.7.1 were not found.
    To resolve this, install the Developer Pack (SDK/Targeting Pack)
    for this framework version or retarget your application.
    You can download .NET Framework Developer Packs at
    https://aka.ms/msbuild/developerpacks

[fail]: OmniSharp.MSBuild.ProjectManager
        Attempted to update project that is not loaded:
         c:\myunityproject\Assembly-CSharp.csproj

The Error message said: "NETFramework Version=v4.7.1 is not found".

okay then, Download & install it from the official website.

Microsoft Official - .NET Framework Version 4.7.1 Download Page - . https://dotnet.microsoft.com/en-us/download/dotnet-framework/net471

Download Page