Question

We have set a custom 404 error page in order to display a ‘nice’ page instead of the default IIS page.

When trying to access a non existing page with a known file extension (e.g. http://mydomain/dumb.aspx), the custom 404 page gets displayed.

When trying to access a file with an unknown file extension (e.g. http://mydomain/index.dumb), the default 404 error page gets displayed.

What puzzles me is that the IIS Web core is handling the error:

ModuleName: IIS Web Core
Notification: 16
HttpStatus: 404
HttpReason: Not Found
HttpSubStatus: 0
ErrorCode: 2147942402
ConfigExceptionInfo :
Notification: MAP_REQUEST_HANDLER
ErrorCode: The system cannot find the file specified. (0x80070002)

But the configured custom error page is note taken into account:

 <httpErrors errorMode="Detailed">
    <remove statusCode="404" subStatusCode="-1" />
    <error statusCode="404" prefixLanguageFilePath="" path="/httpError" responseMode="ExecuteURL" />
</httpErrors>

We do have handler mappings for * but not for . . Could it be the cause of the issue?
What would be the correct configuration?

Answer 1

Just had to change the errorMode attribute of the httpErrors node from Detailed to Custom.

From:

<httpErrors errorMode="Detailed">

to:

<httpErrors errorMode="Custom">