SEL just stopped working

I have been using a SEL controller for about 6 months, mostly for lights and doors. This evening (June 8), it stopped working, i.e. no lights were turned on, etc.
The controller blue light is on. The ethernet cable is working (network is up). I can't log into the controller from my PC or HS3 Touch on my iPhone. I unplugged the controller twice, but I can't get it to work or log into it.
I appreciate your help