Type of “id” (number) in user.json is not supported. Use objects or arrays of objects error when using json-server, why?

I am working on an Angular 4 App. I am trying to get data from a JSON file for building a user dashboard.

I created a json file and tried loading it using JSON server using this: $ json-server --watch user.json and I am getting the following error:

Type of "id" (number) in user.json is not supported. Use objects or arrays of objects..

When I remove the "id" field in the file, I get the same error with "name".

I feel there is something wrong with the way I have created the json files. I am new to web development, so don't mind if it's a very fundamental mistake.

This is my json file:

{
 "id": 1,
 "name":"Kajal Agarwal",
 "department":"Information Technology",
 "college":"Indian Institute of Engineering Science and Technology, Shibpur",
 "subjects":[
    {
        "title":"Data Structures",
        "active":true,
        "faculty":"Prasun Ghosal",
        "notifications":4,
        "color":"#9c27b0"
    },
    {
        "title":"Operating System",
        "active":true,
        "faculty":"Niharika Singh",
        "notifications":0,
        "color":"#ffc107"
    },
    {
        "title":"Algorithms",
        "active":true,
        "faculty":"Debojit Mondal",
        "notifications":1,
        "color":"#009688"
    },
    {
        "title":"Web Technologies",
        "active":true,
        "faculty":"Shantanu Saurabh",
        "notifications":2,
        "color":"#ff5722"
    },
    {
        "title":"Formal Language and Automata Theory",
        "active":true,
        "faculty":"Sudhanshu Sekhar",
        "notifications":3,
        "color":"#03a9f4"
    },
    {
        "title":"Digital Logic and Circuit Design",
        "active":false,
        "faculty":"",
        "notifications":0,
        "color":"#9e9e9e"
    }
  ]
}