Testhost 进程退出并出现错误：您必须安装或更新 .NET 才能运行此应用程序

Question

我最近在构建和部署环境中安装了“.net 6 (SDK 6.0.302)”。现在这些环境已安装以下 SDK：

2.1.504 
2.1.510 
2.1.511 
2.1.518 
2.1.807 
2.1.810 
2.1.811 
3.1.108 
3.1.302 
3.1.414 
5.0.210 
6.0.302  (default)

并安装了以下运行时：

-Microsoft.AspNetCore.All 2.1.8 
-Microsoft.AspNetCore.All 2.1.14 
-Microsoft.AspNetCore.All 2.1.15 
-Microsoft.AspNetCore.All 2.1.19 
-Microsoft.AspNetCore.All 2.1.22 
-Microsoft.AspNetCore.All 2.1.23 
-Microsoft.AspNetCore.App 2.1.8 
-Microsoft.AspNetCore.App 2.1.14 
-Microsoft.AspNetCore.App 2.1.15 
-Microsoft.AspNetCore.App 2.1.19 
-Microsoft.AspNetCore.App 2.1.22 
-Microsoft.AspNetCore.App 2.1.23 
-Microsoft.AspNetCore.App 3.1.6 
-Microsoft.AspNetCore.App 3.1.8 
-Microsoft.AspNetCore.App 3.1.20 
-Microsoft.AspNetCore.App 3.1.22 
-Microsoft.AspNetCore.App 3.1.26 
-Microsoft.AspNetCore.App 5.0.13 
-Microsoft.AspNetCore.App 6.0.6 
-Microsoft.NETCore.App 2.1.8 
-Microsoft.NETCore.App 2.1.14 
-Microsoft.NETCore.App 2.1.15 
-Microsoft.NETCore.App 2.1.19 
-Microsoft.NETCore.App 2.1.22 
-Microsoft.NETCore.App 2.1.23 
-Microsoft.NETCore.App 3.1.6 
-Microsoft.NETCore.App 3.1.8 
-Microsoft.NETCore.App 3.1.20 
-Microsoft.NETCore.App 3.1.22 
-Microsoft.NETCore.App 3.1.26 
-Microsoft.NETCore.App 5.0.13 
-Microsoft.NETCore.App 6.0.6 
-Microsoft.WindowsDesktop.App 3.1.6 
-Microsoft.WindowsDesktop.App 3.1.8 
-Microsoft.WindowsDesktop.App 3.1.20 
-Microsoft.WindowsDesktop.App 3.1.22 
-Microsoft.WindowsDesktop.App 5.0.13 
-Microsoft.WindowsDesktop.App 6.0.6 

目前所有项目都以“.net 3.1”为目标。

就在安装“.net 6”之后，项目在构建/测试/运行时随机抱怨。

出现以下错误：

   error Architecture: x64
   error Framework: 'Microsoft.AspNetCore.App', version '3.1.27' (x64)
   error .NET location: C:\Program Files\dotnet\
   error The following frameworks were found:
   error 2.1.8 at [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
   error 2.1.14 at [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
   error 2.1.15 at [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
   error 2.1.19 at [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
   error 2.1.22 at [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
   error 2.1.23 at [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
   error 3.1.6 at [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
   error 3.1.8 at [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
   error 3.1.20 at [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
   error 3.1.22 at [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
   error 3.1.26 at [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
   error 5.0.13 at [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
   error 6.0.7 at [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
   error Learn about framework resolution:
   error https://aka.ms/dotnet/app-launch-failed
   error To install missing framework, download:
   error https://aka.ms/dotnet-core-applaunch? framework=Microsoft.AspNetCore.App&framework_version=3.1.27&arch=x64&rid=win10-x64

错误 。请检查诊断日志以获取更多信息。

任何想法，关于是什么导致了这个问题。

提前致谢

Answer 1

在 project_name.csproj文件中更改旧的 donet 版本

<TargetFramework>net5.0</TargetFramework>

到最新的

   <TargetFramework>net6.0</TargetFramework>

只需将 5 替换为 6

它将高效运行

Answer 2

我通过升级仍然依赖于 .NetCore 3.1 的解决方案中的 NuGet 包解决了此错误消息。