To fix the above message in STP2, follow the steps below:
Go to Employee Details, select the employee.
Go to Payments, Tax, and select the STP Reporting tab.
Change the employee's Income Type: to CHP and select the Close icon to close and save the screen.
You will get a message regarding the change you are trying to make, select Yes.
Go back to the same Employee Details.
Go to Payments, Tax, and select the STP Reporting tab.
Change the employee's Income Type: to SAW and select the Close icon as previously done in step 3.
You will get the same message regarding the change you are trying to make, select Yes.
Go back into STP2, and the message should be gone.