Quick answer for advanced users
Run sudo chflags -R nouchg,noschg /path/to/file in Terminal to clear lock flags, then try the operation again. If that fails, run diskutil verifyVolume / and diskutil repairVolume / to check the disk.
Let's back up. That error message—'The operation can’t be completed because you don’t have permission to access some of the data' or just 'The operation can’t be completed' with a weird code like -36 or -8080—usually hits when you're copying, moving, or deleting files. It's not a crash. It's macOS throwing up its hands because something's blocking the file.
The most common triggers: you're copying from an external drive formatted as FAT32 or exFAT, you've got a file with a locked flag set, or the disk's permissions went sideways. I've fixed this on countless Macs, and here's the order I use. Don't skip steps—each one rules out a cause.
The numbered fix steps
Step 1: Check for lock flags
Open Terminal (Finder > Applications > Utilities > Terminal). Type this and press Return:
ls -lO /path/to/the/problem/fileLook for the uchg (user locked) or schg (system locked) flags in the output. If you see them, that's your culprit. Clear them with:
sudo chflags -R nouchg,noschg /path/to/the/problem/fileYou'll be asked for your password—it won't show anything as you type, that's normal. After you run that, try the copy again. If the error's gone, you're done.
Step 2: Repair disk permissions (the real fix)
If lock flags weren't the issue, move to Disk Utility. Go to Applications > Utilities > Disk Utility. In the sidebar, select your startup disk (usually called 'Macintosh HD'). Click 'First Aid' and then 'Run'. It'll say 'Checking' for a while—let it finish. It might take 10 minutes or more on a big drive. When it's done, it'll report either 'finished' or 'problems found and repaired'. Either way, try the operation again.
Step 3: Bypass the file system with Finder alternatives
Sometimes Disk Utility doesn't catch everything. If you're still stuck, try copying via Terminal instead of Finder. In Terminal, type:
cp -R /original/path /destination/pathReplace the paths with your actual ones. If cp works, then Finder's metadata handling is the problem. A quick fix: press Command+Shift+. (period) in Finder to show hidden files, then try the operation again. Hidden files like .DS_Store can cause issues, and seeing them lets you delete them.
Step 4: Check the disk format (for external drives)
External drives formatted as FAT32 or exFAT often throw this error when a file name uses characters those formats don't support—like a colon or certain Unicode. If the file name looks weird, rename it. Or reformat the drive to APFS or Mac OS Extended (Journaled), but back up first because reformatting wipes it.
Alternative fixes if the main ones fail
Reboot in Safe Mode
Restart your Mac and hold the Shift key. Safe Mode forces a directory check and clears some caches. After it boots, try the operation again. Then restart normally. This works more often than you'd think.
Check for a stuck process
Open Activity Monitor (Applications > Utilities). Look for Finder or the app that's throwing the error—like Photos or Music. Select it and click the X in the top-left corner to quit it. Then reopen Finder by holding Option and right-clicking the Finder icon in the Dock, selecting Relaunch. That clears a hung process.
Prevention tip
Once you get it working, avoid the nightmare by doing these three things regularly. First, keep your Mac's storage below 90% full—macOS needs room to write temp files. Second, if you use external drives, eject them before unplugging. I know we're all guilty, but that's how the disk gets corrupted. Third, run First Aid every couple months—don't wait for an error to show up.
If you've gone through all these steps and still see that error, it might be a failing hard drive. Back up your data now, and get the drive checked at a repair shop. I've seen too many people lose photos because they ignored that error for months.