If you are receiving the error/usr/bin/crontab permissions are wrong. Please set to 4755 when in the cron section of cPanel, the commands below may correct the error for Redhat/CentOS/Fedora servers.

Log into the server via ssh or the console as root and run:

# yum -y install vixie-cron crontabs
# chmod 4755 /usr/bin/crontab