If you find that there are multiple employees with duplicated payslips you need to check the Payroll data file, where a file may have been loaded twice or the file has duplication in it.
To correct the duplication payslips you need to delete the file and reload the correct one back in, you can do this by following the steps below.
Go to Payroll.
Select Admin Payslips.
Click the Data Files tab.
Check for the duplication using View Data.
Remove the duplication using Remove Data.