Configurator error "could not refresh the iOS update catalog"

I use Configurator (version 1.5) to manage a fleet of about 300 iOS devices at my elementary school. Today when I was in the process of getting a set of iPads ready, I was having issues authorizing one of the free apps I was trying to install. I quit out of Configurator and relaunched it. The Confugurator menu bar appeared, but the window did not open. After about a minute I get a dialog box that says, "Could not refresh the iOS update catalog".

At this point, I restarted my sync computer and tried again. Same result. Restarted again, booted from another volume. Repaired disk permissions a couple of times and got LOTS of repairs.

Still doing the same thing.

Please help!