[c#] HTTP Error 500.30 - ANCM In-Process Start Failure

I was experimenting with a new feature that comes with .net core sdk 2.2 that is supposedly meant to improve performance by around 400%.

Impressive so I tried it out on my ABP (ASP.NET Boilerplate) project

Template asp.net core mvc

I added the following to my web.mv.cproj file


    <PackageReference Include="Microsoft.AspNetCore.App" />
    <PackageReference Include="Microsoft.AspNetCore.Razor.Design" Version="2.2.0" PrivateAssets="All" />

Unfortunately I do not think this version of the ABP framework is compatible as the project simply fails to run and throws: (eventually)

HTTP Error 500.30 - ANCM In-Process Start Failure

I checked the logs after setting stdoutLogEnabled="true" in the web.config and re-trying - but no entries.

Has anybody had any success running the current ABP against a asp.net core in process setup?

I'm thinking this may be something only available in ABP vNext.

This question is related to c# .net-core hosting iis-express http-error

The answer is

When hosting in Amazon Web Services (AWS) using an Elastic Beanstalk (EBS) deployment AND using this stackoverflow answer on how to access configuration values in EBS containers (https://stackoverflow.com/a/47648283/78804)

If NO configuration values have been set within the Elastic Beanstalk -> Environments -> [APP NAME] -> Configuration -> Software menu, you will probably see this error.

Setting ANY SINGLE VALUE in the EBS config, makes it go away.

This is probably caused by the configuration-loading block failing to do a null check and the entire website failing un-gracefully because the error is happening during the application Startup phase.

If you are using Visual Studio, and have any instances of it running, close them all.

You should find a .vs sub folder where your Visual Studio solution (.sln file) resides.
Delete the .vs folder and try again with the in-process hosting model.

Issue with development server

In my case it was due to SDK version.
I have installed all latest updates of VS 2019 but it was not enough.
Error happened when I tried to start web application with VS development server (IISExpress/Kestrel).

So to fix that I just downloaded and installed latest dotNetCore SDK.
For that moment it was version 3.1.2.
And problem is solved!

For me, everything was just fine but the issue was due to publishing by different VS versions, weird !!! (latest VS 2019 (16.4.2)). When I publish the application with VS 2017 it works fine.

The actual issue is in its dependency json file (e.g. MyWebApp.deps.json) in the publish folder. Hope it helps someone.

enter image description here

I had a similar issue when attempting to switch to from OutOfProcess hosting to InProcess hosting on a .Net Core project which I had recently upgraded from 2.0 to 3.0.

With no real helpful error to go on and after spending days trying to resolve this, I eventually found a fix for my case which I thought I'd share in case it is helpful to anyone else struggling with this.

For me, it was caused by a few Microsoft.AspNetCore packages.

After removing all of the referenced Microsoft.AspNetCore packages that had version less than 3.0.0 (there was no upgrade available >= 3.0.0 for these) this error no longer occurred.

These were the packages I removed;

<PackageReference Include="Microsoft.AspNetCore" Version="2.2.0" />
<PackageReference Include="Microsoft.AspNetCore.App" Version="2.2.8" />
<PackageReference Include="Microsoft.AspNetCore.Server.IISIntegration" Version="2.2.1" />
<PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="2.2.0" />

All other Microsoft.AspNetCore packages with version greater than or equal to 3.0.0 worked fine.

I got the same error on my development machine running Windows 10. The error did not go away after I installed dotnet core hosting bundle. I had to go to Event Viewer to get the detailed error. Your underlying issue (if any) may be different than mine. Point is, if you're on a Windows machine, Event Viewer is there to provide details. Hope this helps someone.

event viewer provided error details

I have met this problem because I edit the Program.cs and I delete the Run function. Just add it again:

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Just in case this helps anyone that may have made the same mistake I did.

My website has a SSL certificate by Certify the Web.

When I published, I deleted the _Well-Known folder and this error came up.

enter image description here

Had I not emptied my recycle bin 30 seconds before I figured this out on my virtual machine, I could have just restored the folder.

Instead, I re-requested my certificate, restarted that site and the issue was resolved.

This publish profile setting fixed for me:

Configure Publish Profile -> Settings -> Site Extensions Options ->

  • [x] Install ASP.NET Core Site Extension.

HTTP Error 500.30 – ANCM In-Process Start Failure” is moreover a generic error. To know more information about the error

Go to Azure Portal > your App Service > under development tools open console. We can run the application through this console and thus visualize the real error that is causing our application not to load.

For that put, the name of our project followed by “.exe” and press the enter key.

In may case it was just a typo which corrupts and prevents parsing of JSON settings file

In my case I had recently changed a database connection string in my appstettings.json file. Without logging or error catching in place I suspect this error wound up causing the "HTTP Error 500.30 - ANCM In-Process Start Failure" error.

I happened to notice the exchange between x-freestyler and Tahir Khalid where Tahir suggested an IOC problem in startup. Since my startup had not changed recently but my appstettings.json had - I determined that the connection string in my appstettings.json was the cause of the problem. I corrected an incorrect connection string and the problem was solved. Thanks to the whole community.

Make sure that your *.deps.js json file copied correctly to the deployed location

I Had the same problem that made because I did this in Startup.cs class and ConfigureServices method:

services.AddScoped<IExamle, Examle>();

But you have to write your Interface in the first and your Class in the second

I looked at the Windows Logs under Application. It displayed the error message and stack trace. I found out I was missing a folder called node_modules. I created that folder and that fixed it.

I did not make any changes to web.config or the project file. My .NETCoreApp version was 3.1

ASP.NET Core 2.2 or later: For a 64-bit (x64) self-contained deployment that uses the in-process hosting model, disable the app pool for 32-bit (x86) processes.

In the Actions sidebar of IIS Manager > Application Pools, select Set Application Pool Defaults or Advanced Settings. Locate Enable 32-Bit Applications and set the value to False.

Source: https://docs.microsoft.com/en-us/aspnet/core/host-and-deploy/iis/?view=aspnetcore-3.0#create-the-iis-site

I have encounter issue with .net core 3.1. I have tried all the solution but did't work for me. Then I looked into IIS Log . The issue was Application unable to make connection with database because coonection string was invalid. So Please Look into IIS log to find the issue It may be any exception comes at runtime

I got this problem when my Azure service was immediately trying to get a secret from Azure KeyVault and I had forgotten to give the service permission by KeyVault.

In my case it was a wrong value in appsettings.json file. The value was .\SQLEXPRESS and it worked after i changed it to .\\SQLEXPRESS

I encountered this issue on an Azure App Service when upgrading from 2.2 to 3.1. The reason ended up being the "ASP.NET Core 2.2 (x86) Runtime" Extension was installed on the App Service. Removing that extension from Kudu fixed the issue!

In my case, non of above solution worked. But when I removed myproject.vspscc file from solution explorer, the problem solved.

I had an issue in my Program.cs file. I was trying to connect with AddAzureKeyVault that had been deleted long time ago.


This error could come to due to any silly error in the application. Debug step by step your application startup process.

I found another issue that starts out giving the same error message as in the question. I am sharing this here so that before changing the project file you can make sure your services are properly registered.

I am also running .netcore 2.2 and was receiving the same error message so I changed project file from InProcess to OutOfProcess as in the selected answer. After that I found the real cause for my issue when I received “Cannot instantiate implementation type” : The cause of this was for me was having:

services.AddScoped<IMyService, IMyService>();

instead of

services.AddScoped<IMyService, MyService>();

Related post: Why am I getting the error "Cannot instantiate implementation type" for my generic service?

In my case it was database connection problem. This error needs to be more clear. I hope they will do it in the future. Basically it is a problem at ConfigureServices function in Startup. My advise is try to add all lines try catch in ConfigureServices function and you can findout where is problem.

I had a runtime error in Startup.cs. Schoolboy error - I made a small tweak to that file, but didn't run my app locally before deploying to Azure. The app didn't startup successfully and I got the 500.30 error page.

Removing the AspNetCoreHostingModel line in .cproj file worked for me. There wasn't such line in another project of mine which was working fine.


For me it was wrongly injected DBContext in HostedService. I rewrote it according to this:

How should I inject a DbContext instance into an IHostedService?

and all worked fine!

After spending an entire day fighting with myself on deciding to host my asp.net core application on IIS with InProcess hosting, i am finally proud and relieved to have this solved. Hours of repeatedly going through the same forums, blogs and SO questions which tried their best to solve the problem, i was still stuck after following all the above mentioned approaches. Now here i will describe my experience of solving it.

Step 1: Create a website in IIS

Step 2: Make sure the AppPool for the website has .Net CLR version set to "No Managed Code" and "Enable 32-bit Applications" property in AppPool -> Advanced Settings is set to false

Step 3: Make sure your project is referencing .Net core 2.2

Step 4: Add the following line in your startup.cs file inside ConfigureServices method

services.Configure<IISServerOptions>(options =>
     options.AutomaticAuthentication = false;

Step 6: Add the following Nuget packages

Microsoft.AspNetCore.App v2.2.5 or greater

Microsoft.AspNetCore.Server.IIS v2.2.2 or greater

Step 7: Add following line to your .csproj file


Step 8: Build and publish your code (preferably x64 bitness)

Step 9: Make sure you added your website hostname in etc/hosts file

Step 10: Restart World Wide Web Publishing Service

Now test your asp.net core application and it should be hosted using InProcess hosting In order to verify whether your app is hosted using InProcess mode, check the response headers and it should contain the following line

Server: Microsoft-IIS/10.0 (IIS version could be any depeding on your system)

Update: Download and Install ASP.Net Core Hosting Bundle which is required for it to work

Download the .NET Core Hosting Bundle installer using the following link:

Current .NET Core Hosting Bundle installer (direct download)

  1. Run the installer on the IIS server.
  2. Restart the server or execute net stop was /y followed by net start w3svc in a command shell.

Because the application crashes. For whom saving time on this exception!

And the error code says it throws an exception because it can't find a file in the initial phase. See the Environment Settings section. In my scenario, it worked when I changed the following code

var environment = whb.GetSetting("environment");


var environment = "Development";// whb.GetSetting("environment");

Because I have appsettings.development.json but I didn't have appsettings.production.json. Why it can't find any file because it's looking for different thing on right place.

Resolved my issue by running dedicated App Pool for AspNetCoreModuleV2


HTTP Error 500.34 - ANCM Mixed Hosting Models Not Supported

I was running multiple applications under the same App Pool. Some of the applications were running

<add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModule" resourceType="Unspecified" />

The application causing the error was running AspNetCoreModuleV2

<add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModuleV2" resourceType="Unspecified" />

I created a new App Pool dedicated for AspNetCoreModuleV2 and it resolved my issue.

For us, it was after install EF 5 on an existing core project.

On the PC of my colleague, after a publish, he was having this DLL file : mscordaccore_amd64_amd64_4.700.20.20201.dll

And me, this one :

After his publish to release, the website returned the HTTP Error 500.30.

After my own publish to release, the website was working fine.

With .Net Core 2.2 you should be able to use the InProcess hosting model, since it is naturally faster: everything is processed in IIS, without an extra HTTP-hop between IIS and your app's Kestrel server. One thing you might want to do is add this tag: AspNetCoreModuleV2 Notice the new AspNetCoreModuleV2 vs older AspNetCoreModule option. Another important thing to do is, examine Windows Application Event Log, to identify the culprit. Although error messages there may be cryptic, occasionally, they point to the exact line numbers in the code that caused the failure. Also, in case you use CI/CD with TFS, there maybe environment variables in appsettings.json file that were not properly replaced with their designated values, and this was one of the exception sources for me.

From ASP.NET Core 3.0+ and visual studio 19 version 16.3+ You will find section in project .csproj file are like below-


There is no AspNetCoreHostingModel property there. You will find Hosting model selection in the properties of the project. Right-click the project name in the solution explorer. Click properties.

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Click the Debug menu.

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Scroll down to find the Hosting Model option.

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Select Out of Process.

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Save the project and run IIS Express.

UPDATE For Server Deployment:

When you publish your application in the server there is a web config file like below:

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change value of 'hostingModel' from 'inprocess' to 'outofprocess' like below:

enter image description here

Well for me I had a complicated app startup in which I had created my own WebHostBuilder. This worked fine but failed when I tried the InProcess hosting mode. I assume there was something I missed calling in WebHostBuilder. So I made sure I always call WebHost.CreateDefaultBuilder(args), then make any extra changes - basically as the new app templates do.

Or for asp core 3.1 templates which use IHostBuilder (not IWebHostBuilder), call ConfigureWebHostDefaults

 public static IHostBuilder CreateHostBuilder(string[] args) =>
            .ConfigureWebHostDefaults(webBuilder =>
                // add stuff here

Wow, there are a lot of answers on this question, but I had this same issue and my solution was different from anything I read here, and also quite simple.

I had been having issues with deploying my app to azure with the right environment settings, so I was messing with the launchsettings.json file, and I had changed the value of the ASPNETCORE_ENVIRONMENT variable in the IIS profile from "Development" to "Production". Changing it back to "Development" fixed the issue for me.

  "profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"

Plz see my prev answer in this same thread to understand the whole. Sorry for multiple answers

After further investigation, the issue was happening due to VS 2019 picks the latest patch(default behavior of VS) of .net core 2.2 which is 2.2.8 for me to publish the application. We can restrict this to a specific version of choice by using


See Here. This finally solved my issue even though the latest patch is not applied. I can build from any VS 2017 or VS 2019, both publish the application for .net core 2.2.0 runtime version

enter image description here

I had the same error and the issue was with Microsoft.Extension.Primitives version of the package was not compatible with the .net core version. And this was referencing from one of the projects references from my project was referencing.

Once I had changed the Microsoft.Extension.Primitives in that project. This issue got fixed.

In the Azure event logs, check what error you are getting and if it is related to a package reference. Try the above thing that I have mentioned.

Since nuget packages are tightly coupled with the .net version. Just have to make sure all packages referencing to the project should also be tightly coupled with the .net version.

i was having same issue in my asp 3.1 core , the error was missing a json dependency file so i had to add it to wwwroot/ExternalDependencies in azure

All i'm going to say in this answer is make sure you uh... don't have anything similar to this in your service registration code..

        while (!Debugger.IsAttached) {

This totally did not happen to me and definitely did not make me a very sad boy after 3 hours of screwing around with all of the above answers and more.

I just had the same the same issue. It turned out it was a stupid mistake on my side.

In the ServiceCollection I tried to register an abstract class

services.AddScoped<IMyInterface, MyClasss>();

where MyClass was abstract for some unknown for me reason hehe :)

So guys if you got HTTP Error 500.30 - ANCM In-Process Start Failure Just review your ServiceCollection

In my case, I had a migration which was failing when run on a specific environment in Azure, but running fine in dev. As we have the service configured to run the migrations as part of startup, the actual startup of the web app fails.

I ran the migration manually on the environment to discover the problem, then adjusted it to deal with the data differences on that environment.

If anyone knows how I could have seen the migration error without manually running in directly on the DB, that would be useful.

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