Lightroom doesn't recognise my NEF-files (Nikon Z6)

Also, about the security in Catalina. About what some may confuse with access rights. An issue with application rights.

Outside of Lightoom  Classic. In the MACOS, on the MAC, bring up System Preferences, select Security and Privacy, select the Privacy tab, scroll down to Files and Folders. For Lightroom Classic make sure all boxes are checked.

https://nektony.com/duplicate-finder-free/folders-permission

Hi!
Thank you for your reply. I have tried to change hard disc, but it didn't solve the problem. One thing I noticed is that I can't preview the photos in Finder  as usual – it seems that they are only «Smart Previews» in Lightroom. As I mentioned in my first post: A random photo has this info:  «48,393,216 bytes (4 KB on disc)».

Sounds like you either deleated or moved the original photos, the RAW files, outside of Lightroom Classic. The library previews still exist because you did not remove the photos from within Lightroom Classic.

When you look at that hard drive location for the photos, you apparently cannot see the NEF files, just JPEG files that are librat]y previews?

Now, cross your fingers. Did you perhaps move them as opposed to delete?

From Lightroom Classic, note the filename for the missing photo(s) , well at least one. Use Finder to search for it. Make sure all drives are up and running.

see this article for general info on missing photos:

http://www.computer-darkroom.com/lr2_find_folder/find-folder.htm

Also check the new Catalina security app for permissions you may need to enable for Lightroom.

Also check the disk and folder permissions to verify that you have READ and WRITE privs.

One more problem which I have seen is communication between external hard disc and Lightroom or laptop/computer. In the case where I was assistent the problem was solved by replacing hard disc but that does not mean that you have same or similar problem. Just to mention one more potential source of problem that I have witnessed.

When I open the photos in Develop-mode, I get the message «The file could not be found» and «The photo is missing», but they show up in Finder.

Lightroom cannot find the photos. They are not in the folders that Lightroom expects them to be in. This can be caused by two possible things (maybe more than two, but that's all I can think of right now):

1. You are looking in Finder in a different folder than the one Lightroom thinks the photos are in
2. The capitalization problem, which causes the same folder to appear twice (or more than twice) in the Folder Panel

Please confirm you are looking in the same folder that Lightroom is looking in. Please confirm that this folder in Lightroom appears in the Folder Panel only once by expanding all master folders.