after the most recent update, any time you place something that could potentially be used by a box, even if you have such usage disabled (such as burner structures), outputs messages to the chat log. it's not because debug's on, debug's off, and attempting to turn it on and off again doesn't help. also, when debug's on, it outputs even more to the chat log.
the message being spammed is something like:
[Ammo-Loader]:> Force Player: A total, B slots, C inserters, D chests, E storage chests
where A-E are numbers
it's annoying. and when placing turrets in order to fight enemies, it's lethal, considering it blocks half the screen with text