Toolbox throws "Unexpected error. Limit 3 referencing to metric id 7 which has not been found."

Issue

• When I export an application plan via 3scale toolbox, it throws this error:

  $ 3scale application-plan export a_remote_3scale api basic -k
  {
    "code": "E_3SCALE",
    "message": "Unexpected error. Limit 3 referencing to metric id 7 which has not been found",
    "class": "ThreeScaleToolbox::Error"
  }