Unable to configure HTTPS endpoint. No server certificate was specified, and the default developer certificate could not be found.

Problem:

During development in Visual Studio, ASP.Net Core WebAPI project started throwing this error.

Unable to configure HTTPS endpoint. No server certificate was specified, and the default developer certificate could not be found. To generate a developer certificate run 'dotnet dev-certs https'. To trust the certificate (Windows and macOS only) run 'dotnet dev-certs https --trust'.

Solution:

As suggested in the error message, we have to run the command dotnet dev-certs https.

• First close the browser or stop Visual Studio debugger if you are directly running from Visual Studio.

• Open the command prompt, go to the project's root folder and run this command.

   dotnet dev-certs https --clean
  

  It cleans all HTTPS development certificates from the machine. It will give you following message.

  Cleaning HTTPS development certificates from the machine. A prompt might get displayed to confirm the removal of some of the certificates.

  It may give you a prompt for the removal of certificate, if so, just accept.

• Second run this command:

   dotnet dev-certs https -t
  

  To make it trust the certificate on the current platform.

Deploy ASP.NET Core app in IIS

Hosting models

ASP.Net Core apps support two hosting models.

In-process hosting model

In-process hosting provides improved performance over out-of-process hosting because ASP.NET Core app runs in the same process as its IIS worker process.

Out-of-process hosting model

In this model, ASP.NET Core Module is required for process management, because ASP.NET Core apps run in a process separate from the IIS worker process. The module starts the process for the ASP.NET Core app when the first request arrives and restarts the app if it shuts down or crashes.

Install the .NET Core Hosting Bundle

The ASP.NET Core Module allows ASP.NET Core apps to run behind IIS. You can install .NET Core Hosting Bundle on the hosting system, This bundle installs the .NET Core Runtime, .NET Core Library, and the ASP.NET Core Module.

Create IIS website

• In IIS Manager, Right-click the Sites folder. Select Add Website from the contextual menu. Enter a Site name and set the Physical path to the app's published folder path. Provide the Binding configuration, enter Host name and click OK.

  

• Under Application Pools, Right-click the site's app pool and select Basic Settings from the contextual menu. In the Edit Application Pool window, set the .NET CLR version to No Managed Code.

  

• For ASP.NET Core 2.2 or later: For a 64-bit (x64) self-contained deployment that uses the in-process hosting model, you need to disable the app pool for 32-bit (x86) processes. For this, In the Actions sidebar of IIS Manager > Application Pools, select Advanced Settings.

  

• Locate Enable 32-Bit Applications and set the value to False.