Error adding new Calendar in iCloud on PC due to maximum limit

I am trying to add a new calendar in iCloud on the PC. When I click on the '+' to add a new calendar and name it, I get an error message saying "Couldn't create New Calendar. Creating a new calendar would exceed the maximum number of calendars." I currently have one calendar. Any suggestions?

[Re-Titled by Moderator]

Original Title: iCloud Won't Let Me Add New Calendar - Error Saying It Would Exceed the Maximum Number