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This article applies to Code42 for Enterprise version 4.

Code42 Support

Unable to install CrashPlan app after upgrading or reinstalling Mac OS X 10.6

This article applies to Code42 for Enterprise version 4.


After upgrading to or reinstalling Mac OS X 10.6, CrashPlan installation fails with a message saying: The installer encountered an error that caused the installation to fail.


  • CrashPlan app
  • Mac computers that have upgraded to or reinstalled Mac OS X 10.6

Recommended solution

  1. Open Terminal (Applications > Utilities > Terminal).
  2. Copy and paste the text below into Terminal to change file permissions on the old CrashPlan app:
    sudo chflags noschg /Previous\ System/Applications/
  3. Press Enter.
  4. Type your computer's password and press Enter.
    The letters do not display as you type.
  5. Open Finder and press Command-Shift-G.
  6. Paste /Previous System/Applications/ into the dialog box.
  7. Click Go.
  8. Move the to the Trash.
  9. Uninstall and reinstall the CrashPlan app.

Under the hood

During installation of Mac OS X 10.6, the existing system is moved to a folder called Previous System and the new operating system is installed. Toward the end of the installation, Mac OS X copies the information from the Previous System folder to the new operating system.

Because the CrashPlan app is "locked" -- a system-level feature that prevents the app from being moved -- CrashPlan stays in this Previous System folder and the uninstaller can fail to remove this copy of the application.