You made changes to this paycheck that caused the net pay to be recalculated. Because Lock Net Pay is currently selected, however, you cannot save the changes.
To save these changes, you must first select Unlock Net Pay.
Important: Making changes to the net pay on an existing paycheck can result in additional payroll liabilities and may require you to amend payroll tax forms. Be very careful when editing paychecks that have already been saved in QuickBooks and issued to the employee.
About locking and unlocking net pay on a paycheck