Practice CS: Error when saving a Progress Bill Invoice or generating a recurring Bill:INSERT Statement conflicted with TABLE CHECK Constraint 'CK_Sheet_Entry_staff_billing_rate_KEY'

This error will occur if the Staff person you assigned to the Progress Bill doesn't have a rate schedule setup.
To setup a Rate Schedule on Staff person use the following steps:
  1. Go to
    Setup > Staff
    .
  2. Choose the Staff person and click
    Edit
    .
  3. Select the
    Rates
    tab.
  4. Select the
    Add
    button at the bottom of the Rate tab.
  5. Enter an Effective Date and Cost Rate. The cost rate must be a positive number and cannot be zero.