local retval, message = os.rename(mobf_world_path .. "/mobf_settings.conf.new",
				mobf_world_path .. "/mobf_settings.conf")
			if not retval then
				minetest.log(LOGLEVEL_ERROR,"MOBF: failed to swap old conf file" ..
					" to new one: " .. mobf_world_path .. "/mobf_settings.conf" ..
					"(.new): ERR=" .. message)
			end