Skip to content

How to fix HTTP error 500.30 – core app failed to start?

  • by
  • 3 min read

There are more than ever framework options for developers to create and deploy their applications as and when they like. That said, while the entire process has become relatively simpler, there are still occasional bugs and glitches that stump developers from time to time. 

In this article, we’re talking about the “HTTP error 500.30 – core app failed to start” error when deploying an ASP-Core.Net application, the reasons behind the issue and what you can do to fix the problem. 

What causes this problem?

Unfortunately, it’s difficult to pinpoint the exact exception causing this error without going through the deployment logs or Event Viewer to see which process raised the exception. 

From that point, depending on what process raised the exception, the steps required for fixing the issue also differ. However, some common reasons include the following:

  • Missing XML tags in the deployment configuration file. 
  • Invalid write permissions to the target deployment folder. 
  • Azure services and resources aren’t allowed to access the deployment server. 

Also read: How to count files in a directory in Linux?

How to fix this?

Here are four fixes you can try out. 

Validated the appsettings.json file

One of the most common reasons why these apps run into startup errors is because of incorrect configuration files. The best way to ensure all your configurations and settings are in place is to check the appsettings.json and appsettings.production.json files for syntax and any other inconsistencies. 

Top 7 IDEs and Text Editors to code Python, Java, C++, HTML and more

Install the ASP.NET Core framework bundle

Another possible and rather common cause of the error is a missing ASP.NET Core framework installation. Check to see if the correct version of the ASP.NET Core hosting bundle is installed on the target machine and if it’s not, download and install it from the Microsoft Download Center

Check permissions

Check your IIS Manager to see if the IIS _ USERS alias has the proper permissions required to write logs to the App _ Data and Logs folders. This is especially important if you’re running on local IIS and will require full read/write permissions. 

Check for missing XML tags

Check your web . config file for missing XML tags as they can cause startup errors as well. All you have to do is replace this line

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

With this one

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

Also read: Fix: Fatal: Could not set core.folemode to false

Yadullah Abidi

Yadullah Abidi

Yadullah is a Computer Science graduate who writes/edits/shoots/codes all things cybersecurity, gaming, and tech hardware. When he's not, he streams himself racing virtual cars. He's been writing and reporting on tech and cybersecurity with websites like Candid.Technology and MakeUseOf since 2018. You can contact him here: