Facebook graph api returns 400 bad request with correct access token

For people landing here with the same error message but different problem, you can also check, if you have both IPv4 and IPv6 connections, that both IPs (v4 and v6) are authorized in Facebook OAuth parameters (on developer.facebook.com). That solved my problem.

The format of your API call is incorrect. Try the following instead:

GET https://graph.facebook.com/me?access_token=MY_CORRECT_TOKEN&fields=id,name,email

The accessToken in your URL should actually be access_token.