Encountering HTTP Error 500.31 can be a frustrating experience for developers working with ASP.NET Core applications. This error message, “Failed to load ASP.NET Core runtime,” indicates a problem with the runtime environment, which is crucial for the proper functioning of your application.

In this blog post, we will explore common causes behind this error and provide solutions to help you troubleshoot and resolve the issue.

Troubleshooting HTTP Error 500.31 – Failed to Load ASP.NET Core Runtime

HTTP Error 500.31 is a server error that occurs when the ASP.NET Core runtime cannot be loaded for your application. This can happen due to various reasons, such as misconfigurations, missing dependencies, or incompatible runtime versions.

Common Causes and Solutions:

1. Mismatched .NET Core Runtime Version

– Ensure that the installed .NET Core runtime version matches the version specified in your application.
– Update your application’s runtime version or install the required runtime on the server.

2. Incomplete or Corrupted Deployment

– Double-check your deployment package to ensure all necessary files, including the runtime components, are included.
– Re-deploy your application after cleaning up any remnants from previous deployments.

3. Missing Hosting Bundle

– Verify that the hosting bundle (ASP.NET Core Module) is installed on the server.
– Download and install the latest hosting bundle from the official Microsoft website.

4. IIS Configuration Issues

– Check your IIS configuration to ensure it is set up correctly for hosting ASP.NET Core applications.
– Validate the module registration, handler mappings, and application pool settings.

5. Permissions and Security Settings

– Verify that the application pool identity has the necessary permissions to access the application files.
– Ensure that security settings, such as antivirus or firewall configurations, are not blocking the runtime components.

6. .NET Core Module Registration

– Confirm that the ASP.NET Core Module is registered correctly in IIS.
– Use the `aspnetcoremodule` command-line tool to re-register the module if needed.

7. Environment Variables

– Review and set any required environment variables for your ASP.NET Core application.
– Ensure that the server environment variables are configured appropriately.


Troubleshooting HTTP Error 500.31 requires a systematic approach to identify and address the underlying issues affecting the ASP.NET Core runtime. By following the steps by hire tech firms outlined in this blog post, you can overcome the challenges associated with this error and ensure the smooth operation of your ASP.NET Core application.

If the problem persists, consider consulting relevant documentation, community forums, or seeking assistance from experienced developers to pinpoint and resolve the specific issues affecting your deployment.