Hi! Hopefully someone can help me out. I have no photos stored on my desktop 21.5 iMac 2.5 i5 12 GB Ram running latest Sierra. I use my iPad Pro and LR Mobile flawlessly. I went to set up LR CC 2015.10 on my iMac and tried to sync my online albums. It gets to about 200 photos and shuts down. When I restart it says there appears to be a duplicate catalog. I delete the old, try again and the same nonsense. Any ideas?
Please turn off the GPU from the Lightroom preferences and check if that prevent the crash.
Open Lightroom > Edit menu > Preferences > Performance > Uncheck GPU > Restart.
It was already unchecked. Thanks for the info though.