I am trying to create a .qvf file from serialized json with enigma.js but the doSave() method at last shows me error as (node:16376) UnhandledPromiseRejectionWarning: Error: Bad Request

error response

{
  jsonrpc: '2.0',
  id: 96,
  error: {
    code: 400,
    parameter: 'Object write failed.',
    message: 'Bad Request'
  }
}

.then(function(){
  return context.app.doSave();
})