Turn off Asp.net Custom Errors in Web.config

Reasons to Turn Off Custom Errors

1. Disabling custom errors lets the developers see a detailed error information which will include line numbers and stack traces which will help them to identify and fix issues more efficiently.
2. It lets the developers to quickly identify and address errors and they do not require any other steps to see detailed error messages which will help in faster debugging and testing.
3. It also helps in enhancing the security by preventing sensitive information about the application's infrastructure to be exposed.

Read More: How can you become an ASP.NET developer

Disabling Custom Errors

1. Web.config: You can edit the customErrors element in the web.config file.

2. IIS Manager: IIS Manager allows you to set custom errors for your application.

1. Web.config Method

• The customErrors element is located in <system.web> in the web.config section.
• It has a mode attribute that specifies how errors are handled.
• If you disable this property, you can disable custom errors and see actual error messages.
• In Asp.net, there are three error modes to trace an error:
1. Off Mode: This mode is responsible for displaying error messages on local and remote servers in case of an error.
2. On Mode: This mode is responsible for displaying a custom error page with a message on local and remote servers in case of an error. By using this mode, we can show our own custom error messages page for specific errors on local and remote servers.
3. RemoteOnly: This mode is responsible for displaying error messages on remote servers only in case of an error. By using this mode, we can show our own custom error messages page for specific errors on the remote server only.

Example

<system.web>
  <customErrors mode="Off" />
</system.web>

After making this change, save the web.config file and restart the application. If an error occurs, you'll see a detailed error message instead of a friendly error page.

Runtime Error

A runtime error is a problem in code that happens while it is running and causes it to crash.

Compilation Error

When program code is invalid and cannot be converted into machine code, a compilation error occurs.

2. IIS Manager Method

1. Launch IIS Manager.
2. In the tree view, select the website for which you wish to disable custom errors.
3. Select "Properties" from the menu when you right-click on the webpage.
4. Select the "ASP.NET" tab in the properties window.
5. Select the "Edit Configuration" option.
6. Select the "Custom Errors" tab in the configuration editor.
7. Change the "Mode" setting to "Off".
8. Click "Apply" and then "OK" to save your changes.

When you restart your application, the actual error messages will be displayed rather than the custom error pages.

Example:

<configuration>
    <system.web>
        <customErrors mode="Off" />
    </system.web>
</configuration>

Summary

This article explains how to disable custom error pages in ASP.NET so you can see actual error messages for debugging. There are two options: edit the web.config file and use IIS Manager. The article also explains the different error modes available. Consider enrolling in our ASP.NET Certification Course to get your hands on the best step by step guide for ASP.NET