We are releasing the following information notice due to a bug present in all versions of WHMCS, including the latest one (7.10.2).
InvalidArgumentException: Data missing in Carbon.php:425 Error
This is a problem that affects all versions of WHMCS and occurs when using PHP 7.4, which is not yet compatible with WHMCS. It is expected that version 8.0 of WHMCS will already be compatible with PHP 7.4.
When accessing the WHMCS “System Health Status”, the following error will appear:
InvalidArgumentException: Data missing in /path/to/whmcs/cs/vendor/nesbot/carbon/src/Carbon/Carbon.php:425
The solution to the error is very simple, you simply have to use PHP version 7.3.