cron is not working. You would see this error in
/var/log/cron or in some configurations
/var/log/messages. Its panic time!
Just kidding, bad file mode is just permissions. You fix it with :
chmod 0644 /etc/cron.d/your.cron
Also a common one is WRONG FILE OWNER again rather straight forward :
chown root.root /etc/cron.d/your.cron
Note that you need root to be the owner, even tho you can execute it as a non root user.