Recurring problem, i schedule the crone in cpanel, an error is showing

A Database Error Occurred

Error Number: 1048

in mail i found below message : -
/usr/local/cpanel/bin/jailshell: No such file or directory,

and for cron check : -

Column ‘invoice_number’ cannot be null

INSERT INTO ip_invoices (client_id, invoice_date_created, invoice_date_due, invoice_group_id, user_id, invoice_number, invoice_url_key, invoice_terms, invoice_date_modified) VALUES (‘2568’, ‘2015-08-01’, ‘2015-08-16’, ‘0’, ‘1’, NULL, ‘JwrDsRlerperouh’, ‘Pay before due date’, ‘2015-08-31 19:47:49’)

Filename: /home/newsauditor/public_html/os/core/MY_Model.php

Line Number: 207