WHMCS includes features to help keep your data safe, and we recommend taking additional steps to secure your WHMCS installation further. If the system cron configuration is incorrect or it encounters problems when running, you may see problems with automation throughout WHMCS. We recommend moving the crons directory to a custom private directory above your web root to prevent unauthorized web-based access. Troubleshoot and resolve Could not connect to database errors. Troubleshoot and resolve system cron failures. Troubleshoot and resolve system cron invocation frequency warnings. Troubleshoot and resolve Could not open input file errors. Troubleshoot and resolve issues with the system cron job timing out during metrics polling. Troubleshoot and resolve issues with the cron job becoming stuck while executing the system queue. Troubleshoot and resolve issues with the time at which the system cron runs. Troubleshoot and resolve Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 20480 bytes) errors. Troubleshoot and resolve issues with intermittent system cron run failures. Troubleshoot and resolve failing database backups for large WHMCS installations. Admins receive a No input file specified error email every five minutes. When you set up your WHMCS installation, you must set up the system cron job. The system cron controls all of WHMCS's automation, including daily tasks like generating invoices and sending email notifications. Use System Health to view your system environment status and quickly find and address issues. Troubleshoot and resolve timezone-related automation issues, like incorrect timestamps or cron frequency warnings. Troubleshoot and resolve Unable to communicate with the WHMCS installation errors. Troubleshoot and resolve Call to undefined function curl_init() errors. Troubleshoot and resolve Whoops Exception Maximum execution time of 30 seconds exceeded errors.