This happens on my 2014. iMac, 2013. MacBook Pro and 2016. MacBook Pro. After waking from sleep, 4 out 5 times the clock and the battery indicator will freeze, and moving the pointer to them will display a beach ball. After some investigating, I read that someone said that SystemUIServer chrashes and is the culprit. I checked in the activity monitor and yes, the SystemUIServer stops responding. Force closing it fixes the problem (it restarts) but still, it's driving me crazy. The bug started with Sierra Beta, but it went on in the final version as well. I did a clean install of Sierra on my iMac - it was still there. It's there on the factory-installed Sierra on my MBP. It's there after I upgraded all my Macs to 10.12.2 Anyone else has this problem? I don't expect anyone to have a fix, but I'm asking out of curiosity. I hope Apple fixes this, it's really annoying.