Hi Carmen,
Welcome to planDisney!
I am excited to hEAR that you are planning a trip to the Walt Disney World Resort! Although I am not quite sure of the exact message you are seeing when trying to make
advanced dining reservations, I know that making dining reservations can be difficult. Even though everyone can start making dining reservations when their
dining reservation window opens, currently 60 days prior to arrival, remember that there are folks whose arrival date may be before yours whose actual trip may overlap with your dates. If their arrival date is before yours, their dining reservation window would open prior to yours.
In practice, this means that another Guest and you might both need to make reservations for December 27. If their arrival date is before yours, their dining reservation window would open before yours and they could book reservations for December 27 before you could make reservations since Guests can book for the length of stay up to 10 days.
Carmen, if you try to make dining reservations and some dining locations have no availability, keep checking. People do cancel and I have been able to get all of our desired reservations in advance of our trip. Also, try using a dining reservation finder tool. We have had some success with using the free version of one of those services. And keep checking during your trip as well. Some people cancel dining reservations the day prior to the reservation. Keep in mind that some dining locations have not yet reopened so that could also be a reason that you are getting a message that the restaurant is temporarily unavailable.
Magic and memories,
Donyell