Macbook Pro Retina 13 inch Late 2013 My Macbook Pro keeps restarting - or sometimes just trying to restart - when it is sleeping. Typically I find when I return to my Mac after a gap of several hours that it has either restarted itself and is showing the log-in screen or it is showing a message like "Unable to restart because such and such a thing is active". Usually this is because I have an unsaved file open in a Microsoft Office application. I don't remember this ever happening before I was running Yosemite. This weekend I upgraded to El Capitan and was interested to see if the problem might go away but it hasn't. Opening up the Mac on Monday morning I was presented with the "Unable to restart......" message. This doesn't happen every time the Mac sleeps. Maybe two or three times a week. Does anyone have any idea what might be going on?