Friendly URLs can be set on the Setting tab of the page (Edit mode). Make sure to publish the page.

For more information, please see "Friendly URLs".

Legacy Composite C1 versions

On legacy versions (earlier than 1.3), you should have IIS configured properly:

1. Go to IIS/ your site / Properties /Custom Errors tab
2. Find the 404 Error and edit it:
   • Message type: URL
   • URL: /Renderers/FileNotFoundHandler.ashx

Note: Starting from Composite C1 v1.3, it is enough to switch the IIS application pool mode to "Integrated".