That vague error is a pain, right?
You're in the middle of copying files, opening a disk image, or trying to update an app—and boom, macOS throws up The operation couldn't be completed with no real explanation. It's like the system is shrugging at you. Good news: most of the time it's a quick fix.
The fastest fix: restart Finder
If you see this error in Finder, the first thing to try is restarting Finder. It sounds trivial, but it handles a lot of transient file-handle issues.
killall FinderThat command kills the Finder process, and macOS relaunches it instantly. Your windows come back, your Desktop icons reappear. Then try the operation again.
Why restarting Finder works
Finder holds file descriptors for every folder and volume it's browsing. When a device disconnects or a network share drops, those descriptors get stale. The next operation on that path fails with a generic error instead of something useful. Killing Finder releases all stale handles. It's the macOS equivalent of clearing your cache without touching any data.
If it's a specific file or folder: clear the .DS_Store cache
The error often pops up right after you delete a file, or when you try to open a folder that has a hidden .DS_Store file that's corrupted. That file stores view settings (icon positions, sort order) for each folder, and when it gets out of sync, Finder can throw a fit.
Open Terminal and run:
cd /path/to/that/folder
rm .DS_StoreYou'll get a fresh .DS_Store generated on next visit. This won't delete your files—just the display preferences. If you want to nuke all of them system-wide (safe enough):
sudo find / -name .DS_Store -deleteThat takes a couple minutes if you've got a big drive, but it wipes out all corrupted caches at once.
When the error includes a code: -36, -50, or 100000
Sometimes the error message includes a numeric code. That's a gift because it narrows it down.
| Code | What it usually means | Fix |
|---|---|---|
| -36 | I/O error reading or writing the file. Often a bad sector on an external drive. | Run First Aid in Disk Utility on that volume. |
| -50 | Parameter error, usually from Finder fighting with a network volume (SMB or AFP). | Reconnect the share, or disconnect and remount it. |
| 100000 | Generic POSIX error that often appears in Disk Utility or when using Time Machine. | Repair the disk, check permissions, or reformat if it's an external drive. |
Running Disk Utility First Aid
Open Disk Utility (in /Applications/Utilities/), select the affected volume, and hit First Aid. Let it run. If it reports errors and fixes them, try your operation again. If it can't fix it, the drive might be failing—back it up now.
Less common: App Store updates fail with this error
If the error appears when you're downloading or updating an app from the App Store, it's a different beast. The fix is to reset the App Store's daemon cache:
sudo killall -9 softwareupdated
sudo softwareupdate --clear-catalogThen relaunch the App Store. The daemon rebuilds its catalog and your updates should proceed.
Why this works: the App Store caches a list of available updates locally. When that cache gets corrupted—maybe after a failed install or a network hiccup—every subsequent attempt hits the same wall. Clearing the catalog forces a fresh fetch from Apple's servers.
Network shares: the usual suspect
If you're getting this error on files on a network drive (SMB, AFP, or iCloud Drive), the underlying cause is almost always the connection dropping silently. You don't see a disconnect because macOS reconnects lazily.
- Eject the share (right-click and select Eject, or drag it to Trash).
- Reconnect it from Finder's Go > Connect to Server.
- If it persists, try connecting with
smb://instead ofafp://(or vice versa) and see if the error goes away.
The reason that helps: macOS uses different protocol stacks for SMB and AFP. A glitch in one won't affect the other, and some servers are buggy with one protocol but solid with the other. Switch and you might sidestep the whole problem.
Prevention: keep your system from getting into this state
You can't eliminate every instance of this error, but you can reduce how often it shows up.
- Always eject external drives and network shares before disconnecting. Yanking the cable mid-write is the leading cause of that -36 error.
- Run First Aid monthly if you use external drives. It catches bad blocks before they cause I/O errors.
- Keep macOS updated. Some of these generic errors are fixed in point releases—Apple rarely announces them, they just quietly get better.
- Avoid force-quitting Finder when you're in the middle of a large file operation. Wait for it to finish, or you'll leave those stale handles behind.
The next time you see that cryptic message, you'll know what to do. Restart Finder, check for a .DS_Store issue, and if you see a code, head to the table. Nine times out of ten you'll be back to work in under a minute.