.net core IIS 部署 应用程序池停止并报错503

已安装 Hosting Bundle

https://dotnet.microsoft.com/download/dotnet-core/thank-you/runtime-aspnetcore-3.1.2-windows-hosting-bundle-installer

创建无托管的 应用程序池

结果就是IIS日志报错

应用程序池停止，浏览页面显示503…

报错信息如下：

Warning：A listener channel for protocol 'http' in worker process '3260' serving application pool 'apsnetcode3' reported a listener channel failure.  The data field contains the error number.

Error：Application pool 'apsnetcode3' is being automatically disabled due to a series of failures in the process(es) serving that application pool.

查了半天也找不出原因（开发设备上部署正常）

最后发现 Hosting Bundle 需要依赖 C++ …

Download the Microsoft Visual C++ Redistributable for Visual Studio 2015, 2017 and 2019. The following updates are the latest supported Visual C++ redistributable packages for Visual Studio 2015, 2017 and 2019. Included is a baseline version of the Universal C Runtime see MSDN for details.

安装C++后恢复正常：https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads