If theres no withholding to try to match up with those wages and you just need a state ID number to appease the error gods, can you insert the FEIN for that state?

FWIW if you have that Auto calculate box checked on the W2 worksheet, try unchecking that, I feel like that tripped me up before when I had some part year state issues, if you uncheck it, you may be able to leave the entire line blank.