Custom errors in web.config

Some times after hosting web application on the server, we get unexpected error. But we did not get the detailed message for the unexpected error or if we added defaultredirect="error.htm".

<customErrors defaultRedirect="error.htm" mode="On" />

  how can we get detailed message for the unexpected error. Unexpected error may occur on remote or on local server. We can find out exact error message by doing some changes in web.config. Just change Custom error  mode to off.

<customErrors defaultRedirect="error.htm" mode="Off" />

There are three error modes in which an ASP.NET application can work:

1) Off Mode
2) On Mode
3) RemoteOnly Mode

The Error mode attribute determines whether or not an ASP.NET error message is displayed. By default, the mode value is set to "RemoteOnly".

Off Mode

When the error attribute is set to "Off", ASP.NET uses its default error page for both local and remote users in case of an error.

On Mode

In case of "On" Mode, ASP.NET uses user-defined custom error page instead of its default error page for both local and remote users. If a custom error page is not specified, ASP.NET shows the error page describing how to enable remote viewing of errors.

RemoteOnly

ASP.NET error page is shown only to local users. Remote requests will first check the configuration settings for the custom error page or finally show an IIS error. 

Happy Coding!!