macOS 'The operation can’t be completed' error when copying files

You're dragging a folder from your desktop to an external drive, or maybe copying photos from an SD card. The progress bar gets to like 90%, then stops. You get a popup: “The operation can’t be completed because an unexpected error occurred (error code -36).” Or it might say “-50” or “-8084”. Different numbers, same frustration. It happens on macOS Ventura, Sonoma, even Sequoia.

What's actually happening

The error codes mean different things. -36 is usually a permissions mismatch. -50 points to a bad file name or a corrupt .DS_Store file. -8084 means the file system on the destination drive has issues. The common thread: macOS finds something it can't handle during the copy, and it gives up. It's not your file being corrupt. It's the metadata or the file system itself.

Why the normal fix doesn't work

Most guides say “run First Aid in Disk Utility.” That's step one. But if the disk is healthy and you still get the error, the problem is a hidden .DS_Store file inside the source folder. That file stores folder view settings. When it gets corrupted—which happens a lot with older external drives—Finder trips over it.

Fix it: the real steps

Step 1 – Kill the .DS_Store culprit

1. Open Terminal (found in Applications/Utilities).
2. Type this, then press Enter:

   cd /path/to/source/folder

   Don't type the path by hand. Drag the folder from Finder into the Terminal window after typing cd (with a space). That pastes the full path.
3. Now run:

   find . -name ".DS_Store" -delete

   This deletes the .DS_Store files in that folder and all subfolders. It won't hurt anything—macOS recreates them next time you open the folder.
4. Try copying again. If it works, you're done. If not, move to step 2.

Step 2 – Use cp or rsync instead of Finder

1. Instead of dragging in Finder, open Terminal.
2. Type:

   cp -R /path/to/source /path/to/destination

   Again, drag folders for paths. The -R means recursive (copy everything inside).
3. If cp gives you a permissions error, use rsync instead:

   rsync -av --progress /path/to/source/ /path/to/destination/

   The trailing slash after source is important—it copies the contents without creating an extra nested folder.

Why rsync? It handles partial transfers better. If it fails halfway, you can run the same command again and it picks up where it left off. Finder doesn't do that.

Step 3 – Check the destination drive

1. Open Disk Utility (Applications/Utilities).
2. Select the destination drive in the left sidebar.
3. Click First Aid then Run. Let it finish. It might take 10-15 minutes for a large drive.
4. If First Aid finds errors and fixes them, try the copy again.

Step 4 – Rename the file or folder

Sometimes the error is caused by a file name with weird characters—like a colon or a slash. macOS uses those for internal paths, so it gets confused.

1. In Finder, right-click the source folder or file.
2. Select Rename. Change its name to something simple, like “test” with no spaces or special characters.
3. Try copying again.

Step 5 – Copy with ditto for stubborn files

If nothing works, ditto is the nuclear option. It preserves resource forks but ignores permissions issues.

1. In Terminal:

   ditto /path/to/source /path/to/destination

2. If you want verbose output (see what it's doing):

   ditto -V /path/to/source /path/to/destination

What to check if it still fails

• Is the drive formatted wrong? ExFAT drives work fine for small files but choke on large ones over 4GB. Also, ExFAT doesn't support macOS metadata, so .DS_Store files cause errors. Reformat to APFS or Mac OS Extended (Journaled) if you can.
• Is the cable bad? Try a different USB cable. Seriously. I've spent hours debugging file copies only to find a flaky USB-C cable.
• Is the destination full? Check remaining space. macOS sometimes gives this error instead of a “disk full” warning.
• Is it a network drive? Copy to your local desktop first, then to the network share. Network copies fail more often because of timeouts.

Rule of thumb: If you see error -36, start with .DS_Store deletion. If you see -50, rename the file. If you see -8084, run Disk Utility First Aid on the destination. That covers 90% of cases.