Hi Heather, and welcome to planDisney!
Congratulations on making it to your 60-day reservation window. When you get to that point, a new set of fun begins once you can obtain the reservations you desire.
To my knowledge, no known glitches would prevent you from reserving the
Fantasmic! Dining Package (aside from lack of availability). The Fantasmic! Dining Package is really popular, so it is quite possible that all of the reservations are reserved. However, all may not be lost, as a reservation could open anytime before your arrival date. Continue to check the website daily; if an opening appears, that is the time reserve.
While the Fantasmic! Dining Package offers reserved seating which is a great perk; you still have a chance to see
Fantasmic!, just be sure to arrive as early as 90 minutes prior to each show so that you have the best chance of getting a seat.
We will be here if you have additional questions before your
Walt Disney World Resort arrival.
Have a magical experience!
Raquel