What to do about people using the dof_node exploit to crash people on the server

[gamemodes\base\entities\effects\dof_node\init.lua:56] attempt to perform arithmetic on field ‘spacing’ (a nil value)

I keep getting this error when particular “hackers” as they call themselves attack the server or something, my admins for some reason can’t figure out who’s doing it so they can’t ban him. How do I fix this problem?

Fix the nil value in the effect or contact the author of the addon.

I’ve seen this somewhere before, they ran some LUA script that forces players to use the DoF effect, while it increases and increases, this is very hard to tell who it is, if the server’s yours, restart it, or if you’re an admin and have priveleges, then try to admin cleanup stuff