NOTE: This article applies only to OS X 10.10 Yosemite and prior Mac OSes. In OS X 10.11 El Capitan and later, it is no longer possible to repair disk permissions via Disk Utility. For troubleshooting issues on a Mac related to either system or file permissions, there is a tool in OSX called “Disk Utility." This is used for a number of purposes; it can be used for making images of/burning images to removable media, verify suspected corrupted installer images, and verifying the permission