If the term time fraction fields are missing when adding salaries for employees, check that the fields are enabled and set to either Optional or Mandatory:
Go to Setup and click Settings.
Click Field Settings.
Search for FormData_Salary_m.WorkedFraction and click it.
Tick the Include box.
Select one of the below from the Display dropdown:
Optional: The field will be displayed but the information is not needed in order to save an employee's salary line.
Mandatory: The field will be displayed and you cannot add salaries without adding a value in this field.
Click Save.
Search for FormData_Salary_m.TotalFTFraction and repeat the steps above.