How to fix 500.30 - ASP.NET CORE app failed to start

Well after publishing the program on IIS, we have this error

HTTP Error 500.30 - ASP.NET Core app failed to start Common solutions to this issue: The app failed to start The app started but then stopped The app 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 For more information visit: 

After we check stdout log file, this Error appears

 at Microsoft.Extensions.Configuration.FileConfigurationProvider.HandleException(ExceptionDispatchInfo info) at Microsoft.Extensions.Configuration.FileConfigurationProvider.Load(Boolean reload) at Microsoft.Extensions.Configuration.FileConfigurationProvider.Load() at Microsoft.Extensions.Configuration.ConfigurationRoot..ctor(IList`1 providers) at Microsoft.Extensions.Configuration.ConfigurationBuilder.Build() at Microsoft.Extensions.Hosting.HostBuilder.BuildAppConfiguration() at Microsoft.Extensions.Hosting.HostBuilder.Build() at ArtanNet.Program.Main(String[] args) in C:\Users\Administrator\Desktop\ArtanNet\ArtanNet\Program.cs:line 16 

program.cs file code is:

 public class Program { public static void Main(string[] args) { CreateHostBuilder(args).Build().Run(); } public static IHostBuilder CreateHostBuilder(string[] args) => Host.CreateDefaultBuilder(args) .ConfigureWebHostDefaults(webBuilder => { webBuilder.UseStartup<Startup>(); }); } 

web.congig:

<?xml version="1.0" encoding="utf-8"?> <configuration> <location path="." inheritInChildApplications="false"> <system.webServer> <handlers> <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModuleV2" resourceType="Unspecified" /> </handlers> <aspNetCore processPath=".\ArtanNet.exe" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" hostingModel="inprocess" /> </system.webServer> </location> </configuration> <!--ProjectGuid: d6cea5f9-6e6d-4f03-b6e9-1d0fb599d508--> 

and now please help us to fix this error

9 Answers

HTTP Error 500.30 - ASP.NET Core app failed to start is a very generic error message.

To get a more specific exception message you have to set enable ASPNETCORE_DETAILEDERRORS. To do that in Azure Portal follow these steps:

1. Navigate to the Azure Portal and open your App Service application.
2. In the left-hand menu, click on "Configuration".
3. Scroll down to the "Application settings" section and click on the "New application setting" button.
4. In the "Name" field, enter ASPNETCORE_DETAILEDERRORS (without the quotes).
5. In the "Value" field, enter true (without the quotes).
6. Click on the "OK" button to save the setting.

Now when you will open your app an detailed exception will be shown in place of the generic HTTP Error 500.30 - ASP.NET Core app failed to start.

Which Core version are you using? And what Hosting Model you are using? IN Of Process or Out of Process? You can check thios in you csproj file. if you using In of Process, try to change it to

 <AspNetCoreHostingModel>OutOfProcess</AspNetCoreHostingModel> 

I can fix this issue I change program.cs and add webbulder.useiis() in creatHostBuilder

 public class Program { public static void Main(string[] args) { CreateHostBuilder(args).Build().Run(); } public static IHostBuilder CreateHostBuilder(string[] args) => Host.CreateDefaultBuilder(args) .ConfigureWebHostDefaults(webBuilder => { webBuilder.UseStartup<Startup>(); webBuilder.UseIis(); }); } 

We've just encountered this with .net core 6.0.1. The issue turns out to be that our server had both the 64bit and 32bit versions of ASP.NET Core 6.0.1 Shared Framework installed. We removed the 32bit version, rebooted the server, sent a stern email to our server team and all worked fine ;-)

Also this error can show that your application has errors in config files (most common appsettings.json) so it can't be deserialized properly

This error message also comes when you try to install the published package to the ISP-hosted shared IIS server or an ISP-hosted Virtual Machine.

• Deployment mode: Framework-Dependent
• Target Runtime: Win-x64 or Portable

In my case, when I tried to deploy ASP.NET Core 5 application, it occurred due to not setting the change (read/write/delete) permission to the web application folder for the admin user, basically the root folder.

Faced similar issue of timeout while migrating our application from netcoreapp2.0 to .net 6. We were using .UseIISIntegration() in Program.cs. Changing it to .UseIIS() solved the problem.

If you have already checked below

1. Corresponding dotnet runtime is installed (Command: dotnet --info)
2. handler / target framework is specified

Then, try to run your project.dll Command: dotnet your_project.dll

The error shown there can give direction to your troubleshooting.

500.30 can also be a KeyVault configuration issue or a startup issue with the application. In my case, it was that my managed identity did not have get/list on my targeted KeyVault.