Before following these steps, unplug all iOS devices from your computer and quit iTunes.
Mac OS X
From the Finder, choose Go > Go to folder.
Type /var/db/lockdown and press Return.
Choose View > as Icons. The Finder window should show one or more files with alphanumeric file names.
In the Finder, choose Edit > Select all.
Choose File > Move to Trash. You may need to enter an administrator password.
Delete the files in the Lockdown folder but don't delete the Lockdown folder.