HTTP Error 500.0 - ASP.NET Core IIS hosting failure (in-process) in Dot net core 3.1

ASP.NET Core 3.1 Runtime (v3.1.6) - Windows Hosting Bundle

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The same thing happened to me in .net core 3.1. In my case some server roles and features were missing

Checking the Application Event Log I found the error '0x8007023e'

Checking the System Event Log I found a WAS (Windows Process Activation Service) communication error:

Then I installed the following roles and features:

Also I reinstalled ASP.NET Core Module (is a native IIS module that plugs into the IIS pipeline, allowing ASP.NET Core applications to work with IIS)

Finally I had to reassign the app pool to the site, and everything worked (I'm using InProcess model)