Error in calendar.php – Unsupported operand types (string - int)

[Skewis]

Hello,

I’m experiencing a fatal error in WHMCS related to the calendar.php file. The system throws the following error:

TypeError: Unsupported operand types: string - int in /var/www/myfolder/public_html/admin/calendar.php:0
Stack trace:
#0 {main}
 

php8.3, all php extensions is ok.

[Skewis]

The error occurs immediately after creating a recurring entry in the calendar. If the entry is not recurring, the error does not appear.