问VScode中的统一智能感知不起作用，Omnisharp给出了多个错误和警告

EN

Some projects have trouble loading. Please review the output for more details.
Source: C# (Extension)

Target: c:\Users\Drews\My project

OmniSharp server started with .NET 6.0.401
.
Path: c:\Users\Drews\.vscode\extensions\ms-dotnettools.csharp-1.25.0-win32- 
x64\.omnisharp\1.39.0-net6.0\OmniSharp.dll
PID: 6088

[info]: OmniSharp.Stdio.Host
    Starting OmniSharp on Windows 10.0.22000.0 (x64)
[info]: OmniSharp.Services.DotNetCliService
    Checking the 'DOTNET_ROOT' environment variable to find a .NET SDK
[info]: OmniSharp.Services.DotNetCliService
    Using the 'dotnet' on the PATH.
[info]: OmniSharp.Services.DotNetCliService
    DotNetPath set to dotnet
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
    Located 1 MSBuild instance(s)
        1: .NET Core SDK 6.0.401 17.3.1 - "C:\Program Files\dotnet\sdk\6.0.401\"
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
    Registered MSBuild instance: .NET Core SDK 6.0.401 17.3.1 - "C:\Program 
Files\dotnet\sdk\6.0.401\"
[info]: OmniSharp.WorkspaceInitializer
    Invoking Workspace Options Provider: 
OmniSharp.Roslyn.CSharp.Services.CSharpFormattingWorkspaceOptionsProvider, Order: 0
[info]: OmniSharp.MSBuild.ProjectSystem
    Detecting projects in 'c:\Users\Drews\My project\My project.sln'.
[info]: OmniSharp.MSBuild.ProjectManager
    Queue project update for 'c:\Users\Drews\My project\UnityEngine.UI.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
    Queue project update for 'c:\Users\Drews\My project\Assembly-CSharp.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
    Queue project update for 'c:\Users\Drews\My project\UnityEditor.UI.csproj'
[info]: OmniSharp.Script.ScriptProjectSystem
    Detecting CSX files in 'c:\Users\Drews\My project'.
[info]: OmniSharp.Script.ScriptProjectSystem
    Did not find any CSX files
[info]: OmniSharp.WorkspaceInitializer
    Configuration finished.
[info]: OmniSharp.Stdio.Host
    Omnisharp server running using Stdio at location 'c:\Users\Drews\My project' on host 
788.
[info]: OmniSharp.MSBuild.ProjectManager
    Loading project: c:\Users\Drews\My project\UnityEngine.UI.csproj
[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\Drews\My project\UnityEngine.UI.csproj'.
c:\Users\Drews\My project\UnityEngine.UI.csproj
C:\Program Files\dotnet\sdk\6.0.401\Microsoft.Common.CurrentVersion.targets(1220,5): 
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

[info]: OmniSharp.MSBuild.ProjectManager
    Loading project: c:\Users\Drews\My project\Assembly-CSharp.csproj
[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\Drews\My project\Assembly-CSharp.csproj'.
c:\Users\Drews\My project\Assembly-CSharp.csproj
C:\Program Files\dotnet\sdk\6.0.401\Microsoft.Common.CurrentVersion.targets(1220,5): 
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

[info]: OmniSharp.MSBuild.ProjectManager
    Loading project: c:\Users\Drews\My project\UnityEditor.UI.csproj
[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\Drews\My project\UnityEditor.UI.csproj'.
c:\Users\Drews\My project\UnityEditor.UI.csproj
C:\Program Files\dotnet\sdk\6.0.401\Microsoft.Common.CurrentVersion.targets(1220,5): 
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\Drews\My 
project\UnityEngine.UI.csproj
[fail]: OmniSharp.MSBuild.ProjectManager
    Attempted to update project that is not loaded: c:\Users\Drews\My project\Assembly- 
CSharp.csproj
[fail]: OmniSharp.MSBuild.ProjectManager
    Attempted to update project that is not loaded: c:\Users\Drews\My 
project\UnityEditor.UI.csproj
[warn]: OmniSharp.Roslyn.CSharp.Services.InlayHints.InlayHintService
    Inlay hints requested for document not in workspace Location { FileName = 
c:\Users\Drews\My project\Assets\Scripts\Player.cs, Range = Range { Start = Point { Line 
= 0, Column = 0 }, End = Point { Line = 23, Column = 0 } } }
[warn]: OmniSharp.Roslyn.CSharp.Services.InlayHints.InlayHintService
    Inlay hints requested for document not in workspace Location { FileName = 
c:\Users\Drews\My project\Assets\Scripts\Player.cs, Range = Range { Start = Point { Line 
= 
0, Column = 0 }, End = Point { Line = 23, Column = 0 } } }