I just imaged three iMac (Late 2015) running El Capitan, and they can't see the 10.11.4 update available from my internal network's Apple SUS. It found the iTunes 12.3.3 update from it, but it didn't see the OS update that is downloaded, and enabled on the El Capitan SUS.
If I remove my SUS from the preference file (reverting it to Apple's), it can see the update. When I add it again, it doesn't.
All my Yosemite Macs can see, and download all updates available from this internal SUS server.
Anyone seen this?
