Magic Academy Ruins

I have the same problem, and I think I am glitched. I am finished with all the quests, Lisa and Bart has no more "obligatory" tasks, Morty is just standing in the ruins, not doing anything. I can't send the beasts to fight him. The game keeps telling me I have to get Treestache, which I'm not gonna do, not for 60 donuts. I can only release the beasts to get the decorations which are very unimportant now, I have tons of them. No other tasks, nothing. An update came when I logged in a few days ago but nothing changed. I can't fix anything by visiting neighbors or Krustyland.
So i'm gonna lose a full character because of that, that's annoying.