Error: The rate structure requires the following items for historical data

After entering a new or editing a current rate schedule, the following message will be displayed upon selecting Enter to save the staff changes.
"The rate structure requires the following items for historical data:"
This error is caused by a time sheet entry for this staff that doesn’t have a date. To identify the time sheet(s) causing the problem do the following:
  1. Select
    Actions > Time & Expense Entry
    .
  2. Select the Overview Tab.
  3. Filter for Staff ID / is / [[Staff initials]].
  4. Sort the date column to bring the timesheet without a date to the top of the screen.
  5. Enter a date or delete the line item.
The staff rate schedule can now be edited or added to this staff member.