Office program shows unlicensed product message on it if the product is not activated. The program requires an office license key for activation. Here you can find some more issues,
Firstly, If the product key is used in more than allowed devices, it will show you unlicensed in the other devices. Unlicensed software cannot be used. You cannot edit the word files and save them. The unlicensed error message also appears if the payment is overdue for subscription based products.