"Unable to expand" on your Mac means Archive Utility has stopped on a ZIP file. A few errors dominate: Error 1 (Operation not permitted), Error 2 (No such file or directory), and Error 79 (Inappropriate file type or format). Fix each one from the command line when the graphical tool gives up.

What the Errors Mean

macOS Archive Utility displays errors in a standard format: Unable to expand "<name>.zip" into "<folder>". (Error N - description). Each number points to a different problem:

  • Error 1 is "Operation not permitted", a permissions block.
  • Error 2 is "No such file or directory", the ZIP may be missing or the path is broken.
  • Error 79 is "Inappropriate file type or format", the file is not a real ZIP or is incomplete.

Match your error to the number. That tells you which fix to run first.

Error 1 Operation Not Permitted

Check File Permissions

Error 1 means macOS refuses to let Archive Utility read or write the file. Downloads from the internet carry a quarantine attribute that triggers this. Fix it directly:

  1. Right-click the ZIP file and choose Properties.
  2. In the General section, check if the file is locked. Clear the lock.
  3. Open the command line (find it in Applications > Utilities or search for it).
  4. Type unzip filename.zip and press Enter. The unzip command ships with macOS and can bypass permission blocks that stop the graphical tool.

If unzip still fails, copy the ZIP to your Desktop and try again. The original download location sometimes carries restrictions the Desktop does not.

Error 2 No Such File or Directory

Error 2 means the system cannot find the file at the path you gave. The ZIP was moved or deleted after the error message appeared. Special characters or unescaped spaces in the filename cause the same message.

Extract from the Command Line

  1. Open a shell and navigate to the folder containing the ZIP: cd /path/to/folder.
  2. Type ls to list files. Confirm the ZIP is there.
  3. If the filename has spaces, type the first few letters and press Tab to auto-complete. Example: unzip my\ file.zip.
  4. Alternatively, use ditto -x -k filename.zip destination-folder. This command handles path issues that unzip misses.

If the file is gone, check your Downloads folder or Trash. Safari’s Open 'safe' files after downloading option (Safari > Settings > General) automatically unzips downloads. That leaves a folder instead of the ZIP. The original ZIP may be gone.

Error 79 Inappropriate File Type or Format

Error 79 is the most common corruption error. macOS does not recognize the file as a valid ZIP. This happens when the file is not a ZIP at all, is partially downloaded, or was renamed with a .zip extension incorrectly.

Verify the File Is a Real ZIP

A real ZIP file starts with the bytes 50 4B (shown as "PK" in text). Check this on a Mac:

  1. Open a shell.
  2. Type head -c 4 filename.zip | xxd. If the output shows the expected bytes at the start, the file is a genuine ZIP.
  3. Other bytes mean the file is a different format (like .rar or .7z) or corrupted.

A real ZIP that still gives Error 79 is probably incomplete. Redownload the file from the original source. When that is not possible, a rebuild can recover readable entries.

Rebuild the ZIP

If the unzip command reports errors on a real ZIP, a rebuild recovers what is still readable. Run unzip -FF filename.zip. The -FF flag attempts to fix the archive. If that fails, try unzip -f filename.zip to refresh only the files that can be read.

Using the Command Line as a Reliable Alternative

When Archive Utility fails, the command line gives you more control. Two built-in commands extract ZIP files without the graphical interface:

  • unzip filename.zip, the standard tool. Extracts all files into the current folder.
  • ditto -x -k filename.zip destination-folder, an alternative that handles permission and path issues the first command cannot.

Both are already on your Mac. Open a shell, navigate to the folder with the ZIP, and run one of the commands above. A "command not found" error for unzip means you need to install it via Homebrew (not covered here, but possible).

Preventing Future Errors

Stop ZIP problems before they start:

  • Disable Safari’s automatic unzip: go to Safari > Settings > General and uncheck Open 'safe' files after downloading.
  • Let downloads finish completely before opening the ZIP.
  • Rename files with spaces or special characters before zipping them.
  • Keep a backup of the original ZIP until you have verified the extracted files.