Seems its possible to have item entities in the tracked list that were unloaded. You might want to listen for a chunk unload event, and also potentially check the entity's position is loaded.

Better With Addons-0.40hotfix

oof what
actually no it just loads the chunk, that func_180514_a is the method that recreates structures, i will fix this later today

Actually, that seems to be generating the chunk. I have no idea how that would happen.

No idea, but either way, youve got an entity in an unloaded chunk there :P

fixed (finally)