If you are having an issue with your mac waking from sleep after upgrading to the Pubic Beta of macOS Sierra (like I did) AND you have Duet installed, this is what I did to fix it. This problem may be attributed to other apps that have some kind of display driver associated with them.
I completely uninstalled Duet (or so I thought) as was suggested on many articles I found online.
After uninstalling, I was still having the issue. After a bit of digging around I found there was still a key piece of Duet hanging around.
I have to remove the Duet .kext file that was still in the following location:
After removing this, and rebooting, things looks to be good to go!
This was all on my ‘Early 2016 MacBook’. I did not have this issue on my Late 2014 27″ iMac that did not have Duet installed.