Can't Load data from Apple Software Server - OS X Server.app

Hello JAMF Nation,

My ASUS is now throwing a hissy fit and refuses to load SUS data. Everything worked just fine last Friday and no updates occurred over the weekend.

We have our clients pointed our SUS using either a config profile or command line. We've also tried the direct URL

"http://serverDNS:8088/index.sucatalog".

and

sudo defaults write /Library/Preferences/com.apple.SoftwareUpdate CatalogURL http://serverDNS:8088/content/catalogs/others/index-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog

The computers have the correct SUS URL according to

defaults read /Library/Preferences/com.apple.SoftwareUpdate CatalogURL

The error:

softwareupdate -l
Software Update Tool
Copyright 2002-2015 Apple Inc.

Finding available software
Can't load data from the Apple Software Update server.

We've tried re-doing the Server setup using "sudo rm /var/db/.ServerSetupDone" and killing cfprefsd, "killall cfprefsd".

We've tried deleting the Server.app, deleting /Library/Server and re-installing the Server.app. No dice.

Any help would be appreciated!