My employer has put information into Box 15-16 on my W-2 that is inconsistent with what TurboTax allows. How do I override TurboTax so I can enter my W-2 correctly?

W-2 Box 15: X8 (income earned while foreign resident). TurboTax doesn't allow X8. Second part of Box 15 is blank, and Box 16 shows same income amount as Box 1. TurboTax red flags that second part of Box 15 can't be blank if an amount is in Box 16. How do I workaround this? Can TurboTax fix this obvious implementation oversight?