I have looked everywhere using an online guide and I can’t find the last page. I know it’s a flying one because my book of complete with the collection ones. Help
I play Xbox one x
#field guide page The Great Hall
cobalt bough
hushed ravine
It might not be a flying one, there’s a few dragon braziers in the Great Hall section, and Levioso statues, and moth puzzles
hexed arch
There's a dragon brazier that's easy to miss right above the door at the very top of the Grand Staircase leading to the trophy room
whole glade
I have the same issue and I am on a PS4. I believe it's a bug. There was a similar one in another part of the castle and it was just patched on the latest summer update. Since then some of the revelio pages have respawned. I collected them once again and the count was completed (24/24 and 150/150). I saved it, quitted the game and once I returned the count was down again (23/24 and 149/150). I hope this one and the bug from the Haunted Hogsmeade Shop quest (missing the enemies and appearance on the collection tab) will get patched in the next round of updates.