Permissions on external hard drive

The reason why we want you to copy one of those problematic folders from the external disk to the Desktop is so we can see if the Finder has a permissions error as well. In addition, the next step would be to look at the actual permissions on the raw file and folders. But it sounds like you do everything from within Lightroom and do not know how to get to the actual Raw camera files and folders on the disk file system. It is going to be difficult to explain to you how to navigate to those files using Finder or Terminal instead of Lightroom. Yes, Lightroom uses a Catalog system which is really a database. But the original RAW files are not in the database. Since the disk is FAT32 there are no file system permissions. So the permissions problem is either a corrupted FAT32 file system or a damaged Lightroom catalog database.

DId you ever open Disk Utilty and verify the Disk and run a Repair? If that external disk was unplugged without ejecting (unmounting) the drive. It can scramble the FAT32 file system. You might have slept the Mac and unplugged it or the battery died, etc. the Disk Utility might fix it. Check if Lightroom has any sort of catalog repair options as well. There could also be a bad sector where a portion of the catalog resides or where a RAW file resides. That could result in permanent data loss. Do you have a backup copy of this external disk?

If Disk Utility cannot even verify then the disk is failing. Buy Disk Warrior it is the best drive utility for Mac. Another more technical option is to install Homebrew (http://brew.sh) and install ddrescue. It will clone the disk and not stop on errors. MacPorts is an older system than Homebrew mentioned in this blog post about ddrescue. Homebrew is easier to install in my opinion And has the ddrescue utility. https://derflounder.wordpress.com/2012/01/31/using-ddrescue-on-a-failing-hard-dr ive/

You need a second disk as large or bigger than the problem disk. The ddrescue utility aggressively copies the data even if there are errors.

Professional recovery is an option but it is very expensive. Kroll-On-Track is the service we use at work. But we only use them when we can't read the disk at all or if it fails when we clone it to a new disk.

Storing that data on a FAT volume is asking for trouble. Format it for OS X (as HFS.) Doing that will of course involve restoring from a backup.

That worked perfectly. I now have full use of the 3Tb LaCie back. A few clicks. Done in seconds. Thank you.