The computer woke up twice in the middle of the night. The first time, I put it back to sleep. Five minutes later, it woke up again. That time, I shut it down so the problem would not recur. I have not been able to pinpoint a reason for the computer waking up as “wake for network access” is disabled in System Preferences. I can only conclude it’s an issue with El Capitan. I've already sent feedback to Apple for this. Anyone else having the same problem?