400 Bad request when "Generate random datapoint"

[Wingie]

In the "+ Generate random datapoint" click event of http://localhost:3000/datastreams/

 Each child in an array or iterator should have a unique "key" prop. Check the render method of `Datastream`. See https://fb.me/react-warning-keys for more information.
    in div (at Datastream.js:33)
    in Datastream (created by Connect(Datastream))
    in Connect(Datastream) (created by Route)
    in Route (at App.js:26)
    in div (created by Container)
    in Container (at App.js:22)
    in div (at App.js:17)
    in App (at index.js:33)
    in Router (created by ConnectedRouter)
    in ConnectedRouter (at index.js:32)
    in Provider (at index.js:31)

and also the transaction fails with

POST http://localhost:9984/api/v1/transactions 400 (BAD REQUEST)

is this a known issue? I can help to fix this if needed.