Searched for this (and even went through the “map dumpster” thread) but didn’t see it reported. In the library during the Blightreaper finale there are many stacks of books scattered around. Some of these have collision models but some of them don’t! This makes things very confusing if you’re fighting around them and/or want to jump on top of some of them. I don’t have a video to hand but it seemed like about a 50/50 split between real and ghostly so they shouldn’t be too difficult to identify.