Network Nuget Server is returning 404 on the url ending with /nuget/$metadata

Question

I am trying to setup an internal Nuget Server for our company. I know this topic has been discussed thoroughly and I've read a ton of the discussions. I believe I have things almost working except that I'm getting a 404 when putting the Nuget Server's network URL as a source option for Nuget in VS Nuget Package Manage Settings. From watching Fiddler traces, it appears the 404 is being generated by the URL below. This is preceded by the same URL with a 401 challenge. The IIS log shows that I'm authenticated into the site (I've disabled anonymous access and have only allowed Windows authentication.)

https://network-server/MyNugetFeed/nuget/$metadata

I'm setting this up on Windows 2012 R2 and IIS 8.5 using the .Net 4.0 framework. The site has it's own application pool and it's set to run as "Integrated" instead of classic (this seemed to be a common thing that fixed 404's for a lot of people, but not me).

I've checked elmah.axd (locally on the server as it returns 403 when viewed remotely) and there aren't any errors in the log.

I followed this guide to create the Nuget Server project:

http://docs.nuget.org/create/hosting-your-own-nuget-feeds#step-1:-create-a-new-empty-web-application-in-visual-studio

Here are just some of the things I've reviewed:

404 when listing packages via NugetCommandLine

Nuget Server returning 403's and 404's

Installing private feed Nuget packages from packages.config

Unable to download packages from a self hosted nuget server (404 error)

Hosting Nuget Gallery locally via localhost, cannot access its feed from Visual Studio Library Package Manager - returns 404 Not Found

NuGet - Installing Individual Packages reporting "The remote server returned an error: (404) Not Found."

404 on nuget packages link

http://forums.asp.net/t/1800305.aspx