How to Fix or Repair Permissions in macOS Repairing disk permissions on macOS also ensures that particular files have the right permissions to prevent unauthorized access by apps or users that shouldn’t be meddling with those files.
For example, disc permissions ensure that you can start up your Mac, log into your account, print or launch apps, and more. Fixing or repairing disk permissions in macOS ensures that your operating system can access or modify particular files.
