Visual Studio Code'da Bu Hatayı Alıyorum

İyi günler, Unity üzerinden oyun geliştirmeye başladım. Editör olarak ise Visual Studio Code kullanıyorum fakat, Unity ile ilgili tüm eklentileri kurmama rağmen kodlarım otomatik olarak tanımlanmıyor (IntelliSense Çalışmıyor). Birde kurduğum C# eklentisi üzerinden bir hata veriyor, galiba bu hatadan dolayı çalışmıyor.
Hatanın konsol çıktısı;

Starting OmniSharp server at 24.05.2021 10:48:59
    Target: c:\Users\Castollo\Deneme\Deneme.sln

OmniSharp server started.
    Path: c:\Users\Castollo\.vscode\extensions\ms-dotnettools.csharp-1.23.11\.omnisharp\1.37.10-beta.6\OmniSharp.exe
    PID: 3844

[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 16.10.0 - "c:\Users\Castollo\.vscode\extensions\ms-dotnettools.csharp-1.23.11\.omnisharp\1.37.10-beta.6\.msbuild\Current\Bin"
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        MSBUILD_EXE_PATH environment variable set to 'c:\Users\Castollo\.vscode\extensions\ms-dotnettools.csharp-1.23.11\.omnisharp\1.37.10-beta.6\.msbuild\Current\Bin\MSBuild.exe'
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        Registered MSBuild instance: StandAlone 16.10.0 - "c:\Users\Castollo\.vscode\extensions\ms-dotnettools.csharp-1.23.11\.omnisharp\1.37.10-beta.6\.msbuild\Current\Bin"
            CscToolExe = csc.exe
            CscToolPath = c:\Users\Castollo\.vscode\extensions\ms-dotnettools.csharp-1.23.11\.omnisharp\1.37.10-beta.6\.msbuild\Current\Bin\Roslyn
            MSBuildExtensionsPath = c:\Users\Castollo\.vscode\extensions\ms-dotnettools.csharp-1.23.11\.omnisharp\1.37.10-beta.6\.msbuild
            MSBuildToolsPath = c:\Users\Castollo\.vscode\extensions\ms-dotnettools.csharp-1.23.11\.omnisharp\1.37.10-beta.6\.msbuild\Current\Bin
[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.Completion.CompletionOptionsProvider, 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.Cake.CakeProjectSystem
        Detecting Cake files in 'c:\Users\Castollo\Deneme'.
[info]: OmniSharp.Cake.CakeProjectSystem
        Could not find any Cake files
[info]: OmniSharp.MSBuild.ProjectSystem
        Detecting projects in 'c:\Users\Castollo\Deneme\Deneme.sln'.
[info]: OmniSharp.MSBuild.ProjectManager
        Queue project update for 'c:\Users\Castollo\Deneme\Assembly-CSharp.csproj'
[info]: OmniSharp.Script.ScriptProjectSystem
        Detecting CSX files in 'c:\Users\Castollo\Deneme'.
[info]: OmniSharp.Script.ScriptProjectSystem
        Could not find any CSX files
[info]: OmniSharp.WorkspaceInitializer
        Configuration finished.
[info]: OmniSharp.Stdio.Host
        Omnisharp server running using Stdio at location 'c:\Users\Castollo\Deneme' on host 10316.
[info]: OmniSharp.MSBuild.ProjectManager
        Loading project: c:\Users\Castollo\Deneme\Assembly-CSharp.csproj
[info]: OmniSharp.OmniSharpWorkspace
        Miscellaneous file: c:\Users\Castollo\Deneme\Assets\Scripts\LightControl.cs added to workspace
[fail]: OmniSharp.MSBuild.ProjectLoader
        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
[warn]: OmniSharp.MSBuild.ProjectManager
        Failed to load project file 'c:\Users\Castollo\Deneme\Assembly-CSharp.csproj'.
c:\Users\Castollo\Deneme\Assembly-CSharp.csproj
c:\Users\Castollo\.vscode\extensions\ms-dotnettools.csharp-1.23.11\.omnisharp\1.37.10-beta.6\.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:\Users\Castollo\Deneme\Assembly-CSharp.csproj
Received response for /v2/codestructure but could not find request.
Received response for /v2/getcodeactions but could not find request.

Acaba çözüm nedir ?

Çözümü hatanın içinde bulunuyor.

Alıntı

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