Multiple Lightroom Errors
Last week I upgraded from a 2015 MacBook Pro to a 2018 model. I installed a Time Machine backup of the old machine onto the new machine. Yesterday (9/24/18) I updated to macOS Mojave (version 10.14).
I use Lightroom Classic CC (version 7.5) and have recently started using the mobile app to upload photos from my iPhone. I use an external hard drive to store the original versions of the photos. I keep the LR catalog on my laptop's hard drive (as I read that's faster than using it from the external drive).
Today I opened Lightroom from the Adobe Creative Cloud app on my laptop. I began scrolling through a folder of photos, the first I uploaded from the mobile app, and started getting black circles with exclamation points in the upper right corner.
The error says "Lightroom has encountered problems reading this photo. You will not be able to make adjustments to the photo."
This issue so far appears limited to one folder with 823 photos. It's not happening when I spot checking other folders.

Some of the photos in this folder don't show the black exclamation mark, but when I try to develop them, I get a "File access was denied" error.
I also tried to delete (from disk) a photo in this folder and got the message "The file named “IMG_E7413.JPG” could not be moved to the Trash folder." Despite not being able to delete it, I still appear able to edit it. I'm so confused.
Would appreciate any help or insights on what might've caused the problem and how to fix it. Thanks!
Dave
Message was edited by: David Lee
