I created a building that mostly consisted of wood. I was mining, and upon coming up from that mine (two short sessions with saving later) half the building was missing. Most of the wooden logs, planks, slabs and stairs from one half of the building simply vanished. 

The building is around 156, 66, -250. The mining was around 136, 21, -233. 

The building is at an intersection of 4 different chunks. 

I've never seen anything like it. 

I have backups before and after I can provide if useful.