If you haven't installed it yet, better hold off on installing Lightroom CC 6.2 the update that was released a few days ago. There appear to be a number of stability issues with it.
Here some places to follow what's going on with this issue:
Apparently there's an new update from Adobe 6.2.1 that may fix the problem see:
Update 10/9 8 PM Pacific: I agree with Karl's comment below. Tom Hogatry's (the Lightroom product manager) apology for the Lightroom 6.2 release is a good place to express you feelings about this issue.
I'm still a little confused as you why Hogatry doesn't also refer to Lightroom CC 2015.2 as well as Lightroom 6.2. I've not upgraded to Lightroom CC 2015.2 yet and I don't see the alleged fix released this morning (Lightroom CC 2015.2.1) in my creative cloud app. This whole thing is a world class disaster and I don't see that Adobe understands this yet.