Bad request in creating visualization with restful api

[AlanPu]

I'm sending a POST request to /api/saved_objects/visualization/ to create a visualization with json data, the response is saying:
{
"statusCode": 400,
"error": "Bad Request",
"message": "child "id" fails because ["id" is not allowed to be empty]",
"validation": {
"source": "params",
"keys": [
"id"
]
}
}

But I'm not sure where the "id" is missing. How can identify where exactly my json data is wrong?

[Bill_McConaghy]

Can you share the JSON you are posting?

[AlanPu]

This is the json I exported from an existing visualization, and then changed the title and trying to post again back into Kibana:

{
"attributes":{
"title":"Build Types - Test",
"visState":'{"title":"Build Types - Test","type":"pie","params":{"type":"pie","addTooltip":true,"addLegend":true,"legendPosition":"right","isDonut":true,"labels":{"show":true,"values":true,"last_level":false,"truncate":100}},"aggs":[{"id":"1","enabled":true,"type":"count","schema":"metric","params":{}},{"id":"2","enabled":true,"type":"terms","schema":"segment","params":{"field":"buildType.keyword","size":100,"order":"asc","orderBy":"_key","otherBucket":false,"otherBucketLabel":"Other","missingBucket":false,"missingBucketLabel":"Missing","customLabel":""}}]}',
"uiStateJSON":"{}",
"description":"",
"version":1,
"kibanaSavedObjectMeta":{
"searchSourceJSON":'{"index":"84c00a20-5447-11e9-89ec-6f68f2a4d07f","query":{"query":"","language":"lucene"},"filter":[{"meta":{"index":"a6915570-b107-11e8-964d-77ccef18eb1d","negate":true,"type":"phrase","key":"buildType.keyword","value":"","params":{"query":"","type":"phrase"},"disabled":false,"alias":null},"query":{"match":{"buildType.keyword":{"query":"","type":"phrase"}}},"$state":{"store":"appState"}},{"meta":{"index":"a6915570-b107-11e8-964d-77ccef18eb1d","negate":false,"disabled":false,"alias":null,"type":"phrase","key":"project.keyword","value":"ABC","params":{"query":"ABC","type":"phrase"}},"query":{"match":{"project.keyword":{"query":"ABC","type":"phrase"}}},"$state":{"store":"appState"}}]}'
}
}
}

[AlanPu]

Anyone can help on this please?