Senses
成事不足，败事有余/ 成事不足，敗事有餘 unable to help but able to spoil
Unable to do anything right, and likely to ruin things further; describes someone who is more of a hindrance than a help.
成事不足，败事有余/ 成事不足，敗事有餘 more harm than good
unable to accomplish anything but very good at spoiling things; describing someone who is incompetent and only makes matters worse