HTTP Error 500.30 - ASP.NET Core 5 app failed to start

Question

I deploy a .NET Core 5 app with settings:

And the website shows an 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: https://go.microsoft.com/fwlink/?LinkID=2028265

What is causing this error?

Answer 1

There may be a few reasons behind the error which you can only identify by debugging. You can try to debug this error using the steps below:

1. Navigate to the root directory of the application using CMD
2. Run the application using the command dotnet run (yourApplicationName).dll

If there are any errors, they should appear in the output.

Alternatively, you can check "Event Viewer" (search Event Viewer using Windows search) and navigate to

• Windows Logs
  • Application

Update:

dotnet (yourApplicationName).dll

and check http://localhost:5000/ for error

Answer 2

Go there, and try to manually start your project... i.e.

dotnet ServerApp.dll

Answer 3

open Windows Event Viewer, find the error message and click it, open the Detail tab, you will see the exception.

Answer 4

I recently encountered this issue deploying my .net core 5 app to IIS. I am using environment variables for my various envrionments and the web.config that was deployed was missing the xml tags.

Changing this line:

<aspNetCore processPath="dotnet" arguments=".\<your>.dll" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" hostingModel="inprocess"/>

to:

<aspNetCore processPath="dotnet" arguments=".\<your>.dll" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" hostingModel="inprocess">
   <environmentVariables>
        <environmentVariable name="ASPNETCORE_ENVIRONMENT" value="Local" />
   </environmentVariables>
</aspNetCore>

This fixed my 500.30 issue.

I took guidance from @Mohammed https://stackoverflow.com/a/59390437/6155498