Facebook failed login with Permissions error

Problem statement

We want to know what could cause the below permission error when logging in with Facebook.

 "qs": {
      "error": "access_denied",
      "error_code": "200",
      "error_description": "Permissions error",
      "error_reason": "user_denied",
      "state": "ILfaHKFLfeyYYx_k7H6TsbACdddddddd"

Solution

This error could happen when the user declines permission to their profile upon logging in with Facebook (Facebook Social). More information about this here: