HTTP Error 404.17 when accessing Quest Knowledge Portal (227687)

SOLUTION 1

Enable .NET 3.5 components on the server running Quest Knowledge Portal.

Windows Server 2008 R2

1. Open Server Manager
2. Click Features from the tree on the left
3. Click Add Features
4. Proceed through the wizard to add .NET Framework 3.5.1 Features

Windows Server 2012

1. Open Server Manager
2. Select Manage | Select Add Roles and Features
3. Proceed through the wizard to add .NET Framework 3.5

SOLUTION 2

Reinstall ASP.NET (2.9.50727), for example:

%windir%\Microsoft.NET\Framework64\v2.0.50727\aspnet_regiis.exe -i

SOLUTION 3

Revert handler mappings to parent.

1. Go to IIS and highlight the QuestKnowledgePortal site.
2. Double-click on the Handler Mappings icon
3. Click on Revert to Parent on the on the Actions pane (right-hand side)