修改.Net Install Tool的Setings文件：

"  dotnetAcquisitionExtension.existingDotnetPath": [

    {
        "extensionId": "ms-dotnettools.csharp",
        "path": "C:\\Program Files\\dotnet\\dotnet.exe"
    },
    {
        "extensionId": "ms-dotnettools.csdevkit",
        "path": "C:\\Program Files\\dotnet\\dotnet.exe"
    },
    {
        "extensionId": "visualstudiotoolsforunity.vstuc",
        "path": "C:\\Program Files\\dotnet\\dotnet.exe"
    }, 

],