REST Api error with Facebook Login

I’m trying to login through facebook, using the “Login With Facebook SDK” feature, and getting a

'{"code":3038,"message":"Some of required parameters are null"}'

However, I do believe everything is set properly, since this same call was correctly working a few months ago. I came back to this project a week ago and this feature wasn’t working anymore, but there hasn’t been any changes to the API I believe. Can’t get anything out of the logs either.
Here is the curl command with the complete REST request (some information redacted):

curl -H Content-Type:application/json -H application-id:<application-id> -H secret-key:&lt;secret-key&gt; -H application-type:REST -d '{"accessToken":"<accessToken>","fieldsMapping":{"first_name":"FirstName","id":"FacebookID","last_name":"LastName"}}' -v [url=][/url] -X POST

Here is the response

Note: Unnecessary use of -X or --request, POST is already inferred.
* Trying
* Connected to ( port 443 (#0)
* Initializing NSS with certpath: sql:/etc/pki/nssdb
* CAfile: /etc/pki/tls/certs/ca-bundle.crt
 CApath: none
* ALPN/NPN, server did not agree to a protocol
* SSL connection using TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
* Server certificate:
* subject: CN=*,OU=PositiveSSL Wildcard,OU=Domain Control Validated
* start date: Feb 08 00:00:00 2016 GMT
* expire date: Mar 13 23:59:59 2019 GMT
* common name: *
* issuer: CN=COMODO RSA Domain Validation Secure Server CA,O=COMODO CA Limited,L=Salford,ST=Greater Manchester,C=GB
> POST /v1/users/social/facebook/sdk/login HTTP/1.1
> Host:
> User-Agent: curl/7.51.0
> Accept: */*
> Content-Type:application/json
> application-id:<application-id>
> secret-key:&lt;secret-key&gt;
> application-type:REST
> Content-Length: 326
* upload completely sent off: 326 out of 326 bytes
< HTTP/1.1 400 Bad Request
< Server: nginx/1.8.1
< Date: Sun, 22 Jan 2017 16:50:21 GMT
< Content-Type: application/json
< Content-Length: 62
< Connection: keep-alive
< Access-Control-Allow-Headers: Origin, application-id, application-type, Content-Type, secret-key, request, user-token
< Access-Control-Allow-Methods: POST, GET, OPTIONS, PUT, DELETE, PATCH
< Access-Control-Allow-Origin: *
* Curl_http_done: called premature == 0
* Connection #0 to host left intact
{"code":3038,"message":"Some of required parameters are null"}

Can you help me?Thanks in advance.

Well, seems I’ve found the reason of your issue. You don’t need to pass "id":"FacebookID" - we will automatically put it to column ‘id’ (and create it if it not exists). Please try it and let us know about result.

UPD I have created an internal ticket to fix this issue so that it worked as before. You can reference it by it’s ID BKNDLSS-13824.

Thanks Stanislaw. Removing that mapping "id":"FacebookID" resolved the error.
Seems the behaviour changed at some point.

Yes, it seems. I will notify you here once this issue will be resolved and you’ll be able to use previous code without problems.