Prior versions have seemed not to like sleep mode, as when you take a phone call, etc, and while involved with that, the machine goes to some version of sleep, or a power saving mode such as shutting down the display.
Depending on time involved, or other unknown factors, the program has sometimes failed to work afterward. The PROGRAM can be open, but not with a model or drawing open. I have developed the habit of at least saving, and generally closing anything that is open, if I will be away for more than a very short time.
A trip to the bogs, or a slightly longer phone call, anything that may trigger sleep or power saving causes problems. Sometimes just the machine sitting without input for too long, without entering a power save mode at all, and Alibre may freeze the drawing or model. It is ONLY Alibre, so not due to a machine or OS problem.
Perhaps the 2017 version has some change that makes it worse?
I don't think I am going to be downloading 2017 any time soon. I will let the dust settle first.