Update executions is bulk api

I am trying out the update executions in bulk  https://zephyrsquad.docs.apiary.io/#reference/execution/add-tests-to-cycle/update-executions-in-bulk?console=1
but I get error:
In the body I have one execution.id .Any idea what am I doing wrong

{
  "errorType": "ERROR",
  "clientMessage": "We encountered some problems during processing this request. Please try again!",
  "errorCode": 104
}