If you have created Multiple type HR Formulas, and you're working on a Single type employee that mau be the problem.
Multiple type HR Formulas were designed to split the result of the HR formula to multiple different categories/accounts which align with the split of an employee's payroll to multiple payroll accounts.
e.g. you may have Indirect and Direct Payroll Tax accounts that correspond to your Indirect and Direct Payroll accounts.
An employee needs to be designated as a Parent type employee for you to split their payroll in this way, and only Parent employees may use Multiple type HR Formulas.
If you need a Single type employee to use a Multiple type formula, go to Manage Employees, edit that employee, and check the Parent button.