I am having the same problem with the OpenSprinkler Updater, it is stuck on the “Updating Supported Device List” and I have an internet connection. It seems that remote list is its Achilles heel, without it you go nowhere.
My guess is some service is down right now, it would be nice if there was a default list packaged with the updater that it could fall back on.
It does fairly quickly pick up on the latest Firmware version is 2.1.7.
