HTTP 错误 500.31 - 无法加载 ASP.NET 核心运行时，尝试在 nuget 安装 3.1.0 但失败

Question

HTTP Error 500.31 - Failed to load ASP.NET Core runtime Common solutions to this issue: The specified version of Microsoft.NetCore.App or Microsoft.AspNetCore.App was not found. Specific error detected by ANCM: It was not possible to find any compatible framework version The framework 'Microsoft.AspNetCore.App', version '3.1.0' (x64) was not found. - The following frameworks were found: 6.0.1 at [C:\Program Files\do.net\shared\Microsoft.AspNetCore.App] You can resolve the problem by installing the specified framework and/or SDK. The specified framework can be found at: - https://aka.ms/do.net-core-applaunch?framework=Microsoft.AspNetCore.App&framework_version=3.1.0&arch=x64&rid=win10-x64 Troubleshooting steps: Check the system event log for error messages Enable logging the application process' stdout messages Attach a debugger to the application process and inspect For more information visit: https://go.microsoft.com/fwlink/?LinkID=2028526

Answer 1

To run an ASP.NET Core application on a machine, the appropriate runtime (or SDK) must be installed on that machine. In your case, you want to run a .NET Core 3.1 application on a machine that has only .NET 6.0 installed. Therefore, to run your ASP.NET Core 3.1 application, you must download and install the appropriate ASP.NET Core runtime (or for a Windows server with IIS, the appropriate hosting bundle).

Answer 2

You can also solve this in.runtimeconfig.json file

You can set your current version manually.

"runtimeOptions": {
"tfm": "net5.0",
"framework": {
  "name": "Microsoft.AspNetCore.App",
  "version": "6.0.1"
},