https://macmule.com/2013/12/20/itunes-error-you-do-not-have-enough-access-privileges-for-this-operation-45054/

CheckforSharedFolderAndCreateIfMissing.sh

#!/bin/sh
####################################################################################################
#
# License: https://macmule.com/license/
#
####################################################################################################

# Check to see if /Users/Shared exists..
if [ -d "/Users/Shared/" ];
then
    # If /Users/Shared exists, exit...
    echo "/Users/Shared exists.. exiting"
    exit 0
else
    # If /Users/Shared does not exist, create...
    mkdir /Users/Shared/
    echo "Created /Users/Shared/ directory..."
    # Give everyone 777 access to /Users/Shared/...
    chmod -R 777 /Users/Shared/
    echo "Set permissions to 777 on /Users/Shared/..."
fi