We have received the following from the folks at Summon:
the Summon service has experienced interruptions in service. We are aware of the issue and actively working to resolve it. We will follow up again once we have more detail.
It just took well over a minute to get the search screen when I typed “go/summon” in an address bar. I did a very simple search a couple of minutes ago and the connection timed out. A comment to this post will be added when we become aware that service is restored.
Worldwide users of Summon are reporting that it’s functioning again. It appears to be working normally here as well. (It had been down since around 2 am Eastern time.)