Security Update 10.11.6 on iMac Mid 2011 - Sleep / Reboot issue

[PhillyGuy72]

Odd issue overnight for my 2011 iMac on El Capitan. I did the update yesterday with no problems..that was until I put it into sleep mode around 12:30am. I fell sleep only to be awakened by my iMac "Apple startup tune" - bright white boot up screen at 2:05am. my Mac just randomly rebooted itself! And it was a very long boot up I might add. When it finally finished about 6 minutes later..I did put it to "sleep" once again only to have it reboot itself once again at 4:41am! No idea.

After that --- forget it, I shut it down. This is something completely new, and it never happened before the update yesterday.

Any possible quick solution I can do with this, maybe clear out the cache (~/Library/Caches/)
Not sure what is causing this, but I am pretty sure the update did something goofy.

 

[briloronmacrumo]

I did the update yesterday with no problems

Not sure if this refers to an El Capitan update from 10.11.x to 10.11.6 or Apple's recent security update.

I'm not seeing this issue here with the same machine and 10.11.6 without the recent security update.

 

[PhillyGuy72]

Sorry, I meant the security update and Safari.

I looked it up on my console, called a "Sleep/Wake Failure" and a slew of code / "Threads" I can't make out.
I'll see what happens later...odd.

 

[jbarley]

Any possible quick solution I can do with this, maybe clear out the cache (~/Library/Caches/)
Not sure what is causing this, but I am pretty sure the update did something goofy.

The quickest solution would be to reload the backup you made just before doing the updates.

 

[marvz]

I have the same problem.. before 10.12.1 (so on 10.12.) it happened a few times around 2 months ago but lately it never happened again. Then after the 10.12.1 update it happened both nights. Restarted from alone (I put in Sleep mode) and after login I got the message like "your computer restarted because of a problem.. sleep/wake failure". Really annoying.
I have a late 2015 Retina 5k iMac.