littleangie,
Are you trying to book a room-only reservation for 2017 or 2018?
If it is a 2017 date you want, if it appears full online then it probably is full and you would have to keep checking online or calling to see if a cancellation happened and there are now vacancies.
If it is a 2018 date you want, the Disney online system is not yet ready to accept reservations online because 2018 rates are not yet available. Rates for the next calendar year are set in summertime and once they are set, the online tool is updated and the 499 day rule applies there too. BUT - you can call and make a 2018 reservation within the 499 day rule TODAY but you have to CALL. You will be charged for one night as a deposit at the current 2017 rates and once the 2018 rates come out, your reservation will convert to those and you will owe the 2018 total less the deposit paid.
2018 packages either called or booked online have to wait until 2018 rates are set in summer - just the way it is with packages.
It has been this way for a couple years and applies to the Fort as well as the other WDW resort hotels. Here on the Camping Board and the Resorts board, the chatter will start once we get close to time for the next year's rates.
Bama Ed