CCleaner will display a list of mismatched permissions. Disk Utility will again run through a scan, repairing the identified permissions issues.

In the left-hand pane, click Tools, and then click Repair Permissions To repair these issues, click the Repair Disk Permissions button.

To repair permissions using CCleaner for Mac: It's also a good idea to repair permissions before and after performing an OS upgrade. However, this function is no longer needed in macOS 10.11 or higher as it is managed automatically by the operating system, and so is no longer displayed in CCleaner for Mac when running on these versions of macOS. Repairing permissions can often fix these problems. If a file permission gets changed to the wrong value, it can result in crashes and other strange behavior. File permissions tell applications what can and can't be done with programs and other files.

If you find applications are crashing, not starting properly, or acting strangely, permissions may be the problem.

You can also find helpful information about the latest version of our macOS app. Note: this article is relevant to version 1.18.30 of CCleaner for Mac and below.

Mac disk utility repair permissions