After taking note of it's settings, delete the Payroll Control Record for the affected PAA.
Then, re-create the Pay Payroll Control Record but setting the Payroll Period to the previous one.
Next, you will Release Payroll for that PAA, therefore increasing the PP by one to the one you need to transfer to FI/CO, and check what employee numbers are listed in the "Incorrect pers. nos." list.
For each of these employees, you will need to uncheck their "Payroll correction" box in IT0003 (after taking note of their "Earliest MD change" date, and then immediately Exit Payroll.
After doing the FI/CO transfer, once you Release Payroll for that PAA, you will have to manually force retroactive calculation for the employees whose IT0003 you modified.
Message was edited by: Rémi Corriveau
P.S.: Note that you should be able to post to FI/CO the results of the past Payroll Period without having to do anything to the Payroll Control Record, and that even if you have "Released Payroll" for the next Payroll Period.