How can I repair disk permissions on Mac OS X?
If you can’t install or start Skype, repairing disk permissions on your Mac OS X using Disk Utility might solve your problem.
To repair disk permissions on Mac OS X:
Open the Applications folder and select Utilities > Disk Utility.
In the left panel of the Disk Utility window, select your primary hard drive.
In the First Aid tab, click Verify Disk Permissions. Your computer will perform a diagnostic test. Depending on the hard drive size and usage, it can take up to one hour.
When the problems with disk permissions are displayed in the Disk Utility window, click Repair Disk Permissions to fix them.
After the Disk Utility completes the disk permissions repair, restart your computer so that you can install or start Skype.
Learn more on Apple’s website.*
*Skype is not responsible for the content of external sites.