Disk Utility Maintenance
Every user should run regular maintenance on their Mac. The simplest way to do this is to run Disk Utility once a month. To run Disk Utility do the following ...
1. Open the Utilities Folder that is inside your Mac's Applications folder. Path: Applications/Utilities
2. Inside the Utilities folder locate Disk Utilities.
3. Launch Disk Utilities by double clicking on the Disk Utilities Icon. (see below)
4. Once Disk Utility opens, select Macintosh HD in the left sidebar. Then click Repair Disk Permissions. (see below)
5. Let Disk Utilities run. If it repairs a great number of issue, I'd recommend that you close Disk Utilities, relaunch the app and run it a second time.