(minor spoilers)
After finishing the doll's quest (the one with the uncovering memories and stuff), returning to that same area within the oakwood mansion causes an error "Failed to load, Data/Map238.json", perhaps it's only a personal issue, but still thought I'd ask. I also only want to return to that area to collect the purple book that is needed to progress that one side quest.
I play on the apk version of the game btw.