Resolve Daily Cron Not Executing Within the Expected Hour
If you receive an email with the subject WHMCS Daily System Cron Attention Needed that looks like the following, then read on to learn how to resolve the problem.
Your WHMCS is configured to perform the Daily System Cron during the hour of 9 am.
However, the Daily System Cron did not execute within that hour as expected.
This may be due to the scheduled time specified in your web hosting control
panel's cron entry. Please ensure your web hosting control panel executes the
WHMCS System Cron (cron.php) at least once during the hour of 9 am.
If you have confirmed that setting, and you continue to receive this message,
then please refer to the WHMCS Cron documentation to ensure you have itemized the
appropriate command and any additional options.
Please contact WHMCS Support if you require further assistance.
Verifying when your cron runs
Login to your web hosting control panel and navigate to the Crons section (cPanel pictured below).
Navigate to the configured cron commands and look for the one ending with cron.php. This is the WHMCS System Cron.

The above shows our cron is currently configured to run at 11am each day so we need to modify this.
Correcting the cron configuration
The WHMCS System Cron should be configured to run every 5 minutes, so let's go ahead and edit this cron entry (1) and in the Common Settings dropdown menu (2) select "Every 5 minutes"
Click Edit Line to save the changes and verify the cron timing configuration then shows as below.
The cron will now run at the hour you configured within WHMCS from the next day onward.
Additional copies of this email may still be received, but will stop within 24 hours
If you continue to receive these emails after 24 hours (more specifically; after the Configuration > System Settings > Automation Settings Time of Day hour), please refer to the next article for further troubleshooting steps.