Resolving Error 404.17: Serving Files Without Extensions

You may encounter the error "404.17 Not Found - The requested content appears to be script" when trying to serve a file that has no file extension (e.g., a file named simply verify or test).

This is a common issue during SSL Certificate verification (such as Let's Encrypt), where the validator expects to read a text file with no extension inside a .well-known folder. By default, IIS may block these files because it does not know which MIME type to assign to them.

The Solution

To fix this, you need to explicitly tell IIS to treat extensionless files as standard text or HTML files. You can do this by adding a specific MIME map in your web.config file.

Step-by-Step Instructions

1. Access File Manager
   • Log in to the control panel and navigate to the File manager tab for your website.
   • Navigate to the folder containing the file (or the root folder of your site).
2. Create/Edit web.config
   • If a web.config file already exists, edit it.
   • If not, create a new file named web.config.
3. Add the Configuration

   Insert the following XML code. This tells the server to map any file with an empty extension (.) to the text/html content type.

   <?xml version="1.0" encoding="UTF-8"?>
   <configuration>
     <system.webServer>
       <staticContent>
          <mimeMap fileExtension="." mimeType="text/html" />
       </staticContent>
     </system.webServer>
   </configuration>

4. Save
   • Save the file. The file without an extension should now be accessible via the browser.