incompetency

/ɪnˈkɑmpɪtənsi/
noun
  1. The state or quality of being unable to do a job or task properly; lack of skill or ability.
    • The company's financial problems were blamed on the CEO's incompetency.
    • Her incompetency with computers made it hard for her to finish the report on time.
    • The manager was fired for gross incompetency in handling the team.