Just pushed out a hotfix for a bug that could cause unpurchased buildings in the Academy to disappear and not be purchasable, and another situation that may have prevented accessing the academy altogether.
If you were effected by this bug, you should be able to get back into the academy now, and be able to access any buildings that may have been inaccessible.
As a bonus, when you level up, it now tells you what level you leveled up to.
Sorry everyone!