Home » Visual Stuio » HTTP Error 500.30 – ANCM In-Process Start Failure (Solved)

HTTP Error 500.30 – ANCM In-Process Start Failure (Solved)

Visual Studio makes it easy to run your application project by using IIS installed in Windows. You don’t have to explicitly go to IIS Manager and deploy your application there. You can simply click the “Run” (green arrow) icon to view your project on browser.

While trying to run a .NET Core 3.1 application, we came across “HTTP Error 500.30 – ANCM In-Process Start Failure” error. Interestingly, the application compiled successfully. However, it gave this error when we tried to run it.

The entire error message:

HTTP Error 500.30 – ANCM In-Process Start Failure

Common causes of this issue:
– The application failed to start
– The application started but then stopped
– The application started but threw an exception during startup

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

HTTP Error 500.30 - ANCM In-Process Start Failure

In Event Viewer, you will see the error below:

Event ID 1018, IIS Express AspNetCore Module V2

Application ‘/LM/W3SVC/2/ROOT’ with physical root ‘C:\Users\mesahin\OneDrive – Microsoft\Documents\Cases\120011424000352 – Updating .NetCore 2.2 MVC application to 3.1\pubCore1_Net3_1\pubCore1\pgiCore1\’ hit unexpected managed exception, exception code = ‘0xe0434352’. Last 4KB characters of captured stdout and stderr logs:

Application startup exception: System.NullReferenceException: Object reference not set to an instance of an object.

at Microsoft.AspNetCore.Hosting.WebHostBuilderIISExtensions.<>c__DisplayClass0_0.b__2(IISServerOptions options)

Event ID 1018

Root cause

This issue occurs because of mixing library references in the project. For example, if you are upgrading your .NET Core 2.2 application to .NET Core 3.1, you should make sure there is no reference or dependency to 2.2 libraries.

Solution for “HTTP Error 500.30 – ANCM In-Process Start Failure” error

We noticed that the .NET Core solution had a reference to 2.2 version of the Microsoft.AspNetCore library. Removing this reference solved the issue.

HTTP Error 500.30 - ANCM In-Process Start Failure

Once you fix 500.30 error and continue running your application, Visual Studio may stop the process with “Syntax error” and other unexpected messages. Check this post out for step-by-step instructions to solve these issues: How to fix “Declaration expected”, “Syntax error”, and “Statement cannot appear outside of a method” errors


Ned Sahin

Blogger for 20 years. Former Microsoft Engineer. Author of six books. I love creating helpful content and sharing with the world. Reach me out for any questions or feedback.

5 thoughts on “HTTP Error 500.30 – ANCM In-Process Start Failure (Solved)”

  1. Actually in my case, the problem was that appsettings.json was not formatted properly.
    Win uses “\” as a dir separator so in path settings you’ll need to add “\\” instead of \ and it will be Ok

  2. I was also getting the same error in the morning. My application hosted in Azure. It was working fine previous day and somehow today its giving the same error.
    I have been study and gather information about to solve it. I suppose to implement all the recommended points one by one in evening. Before implementing the changes – what I found, is that the site is working fine (in the evening).
    Don’t know why this error appeared in the morning and get resolved in the evening – must be some background process happening by Azure team probably.

    I didn’t do anything meantime.

  3. Hi,

    I am facing the same issue in my application that is hosted in Azure (only on Dev and Test) but the Prod works fine. When i run the application locally, it works fine with no errors. Can some one help me fix this.



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