Bug?

I’m getting an error with this plugin during some processes:

Error Details
=============
An error of type E_ERROR was caused in line 404 of the file /home/ISP/public_html/www.domain.com/wp-content/plugins/uptime-robot-monitor/functions.php. Error message: Uncaught Exception: DateTime::__construct(): Failed to parse time string (@) at position 0 (@): Unexpected character in /home/ISP/public_html/www.domain.com/wp-content/plugins/uptime-robot-monitor/functions.php:404
Stack trace:
#0 /home/ISP/public_html/www.domain.com/wp-content/plugins/uptime-robot-monitor/functions.php(404): DateTime->__construct('@')
#1 /home/ISP/public_html/www.domain.com/wp-content/plugins/uptime-robot-monitor/admin-dashboard.php(38): urpro_sectotime(NULL, 'short')
#2 /home/ISP/public_html/www.domain.com/wp-admin/includes/template.php(1395): urpro_admin_dashboard('', Array)
#3 /home/ISP/public_html/www.domain.com/wp-admin/includes/dashboard.php(274): do_meta_boxes(Object(WP_Screen), 'column4', '')
#4 /home/ISP/public_html/www.domain.com/wp-admin/index.php(181): wp_dashboard()
#5 {main}
  thrown