Classic ASP: Parent Paths and Showing Detailed Errors

This article is for sites that run Classic ASP on a Windows (IIS) hosting package. It covers two things that often trip people up: includes that use ../, and the generic error pages IIS shows by default.

Linux Cloud Hosting doesn't run ASP. If you're not sure which platform your package uses, ask support.

Parent paths are disabled

For security, ASP parent paths are turned off on the platform. Any include that climbs up a folder with ../ will fail.

The fix is to use a virtual include, which gives the full path from your website's root (the folder your domain points to) instead of a path relative to the current file.

Won't work

<!--#include file="../_fpclass/fpdblib.inc" -->

                        
                    

Works

<!--#include virtual="/_fpclass/fpdblib.inc"-->

                        
                    

Two things change: file becomes virtual, and the path starts with / at the site root instead of going up with ../. A search-and-replace across your .asp files usually fixes a whole site in minutes.

Show detailed errors while debugging

By default, Windows Server hides application errors from visitors and shows a generic error page instead. While you're troubleshooting, you can make IIS show the real error in your browser. Create or edit web.config in your site root:

<configuration>
  <system.webServer>
    <httpErrors errorMode="Detailed" />
  </system.webServer>
  <system.web>
    <customErrors mode="Off" />
    <compilation debug="true" />
  </system.web>
</configuration>

                        
                    

If your web.config already exists, add these elements inside the matching sections rather than creating a second <configuration> block.

Turn it off again

Detailed errors can reveal file paths, code and connection details to anyone who visits. When you've fixed the problem, remove these lines, or set errorMode back to DetailedLocalOnly, customErrors to RemoteOnly and debug to false.

Need help?

If something doesn't work as described, open a support ticket from your client area or message us on WhatsApp at 01818160926. Tell us the domain name and what you have already tried, and we'll take it from there.