User not able to use crontab

Symptoms

When attempting to use the crontab command or add/modify a cron job via the cPanel interface, you may see an error like the following.

Description 

If the /etc/cron.allow file exists, then you must be listed (one user per line) therein to be allowed to use this command or add cron jobs via the cPanel or WHM interfaces.

If the /etc/cron.allow file does not exist but the /etc/cron.deny file does exist, then you must not be listed in the /etc/cron.deny file in order to use this command.

Workaround

There are two options for this workaround. 

1. You can add the users that should be allowed to create or manage cron jobs to file /etc/cron.allow.
2. You can rename or remove the file /etc/cron.allow.