Help! I finally updated MacBook Pro to OS Sierra, and since then, Lightroom CC has been freezing in the Develop module. It doesn't completely freeze up, but my preview image won't change, no matter where I click on the bottom filmstrip. It will still change images in the Navigator window (and I can still select images in the filmstrip to delete (or add to a quick collection, etc), but I cannot edit. I CAN, however, batch sync images in the Library Module.
All is fixed when I quit LR and reopen it, but locks again soon. From what I can tell, it locks when I "Delete Rejected Photos" from the Photo menu, but sometimes it seems to happen randomly.
Are you by chance deleting images while in the Develop module? If you are you need to stop doing that for the time being. There is a bug in the newest release that causes this and should be corrected in the next release.
Just go back to the Library module, press the g key to do that, and then delete your unwanted images.
THANK YOU! I'll try that!