NodeJS/Mongoose: Cast to ObjectId failed for value "..." at path "_id" - node.js

Question

On the main page, there is a hyperlink with profile/5aa3cfb783622a145a86d616 that points to the profile page of a user, where 5aa3cfb783622a145a86d616 is the Object ID of the user (it is shown as "_id" : ObjectId("5aa3cfb783622a145a86d616") in MongoDB).
When I click on the link, the page fully loads without any problem. However, the terminal still says Cast to ObjectId failed for value "..." at path "_id" for model "User", and the browser's favicon still shows that it is loading, even though the page has fully loaded.
I tried searching for answers, but none of them are specific to my problem.
EDIT
After playing with the code, I found that the problem seems to lie in the multiple "populate" methods, which I have previously ignored when simplifying the questions, as I thought there was no issue with it. I now include the full code below.
Inside the User document, there is a Post array containing the Post's ID. Each post document has Author, Likes, and Comment. In the Comment array, each comment document has the Author's ID. All of these have to be populated.
NodeJS/Mongoose:
router.get("/:id", function(req, res){
User.findById(req.params.id).populate({
path: 'posts',
populate: [{
path: 'author',
},
{
path: 'likes',
},
{
path: 'comments',
populate: [{
path: 'author'
}]
}]
})
.exec(function(err, user){
console.log(user);
res.render("profile", {user: user});
});
});
User Schema
var UserSchema = new mongoose.Schema({
posts: [
{
type: mongoose.Schema.Types.ObjectId,
ref: "Post"
}
]
});
Post Schema
var postSchema = mongoose.Schema({
author: {
type: mongoose.Schema.Types.ObjectId,
ref: "User"
},
likes: [
{
type: mongoose.Schema.Types.ObjectId,
ref: "User"
}
],
comments: [
{
type: mongoose.Schema.Types.ObjectId,
ref: "Comment"
}
]
});
Comment Schema
var commentSchema = mongoose.Schema({
author: {
type: mongoose.Schema.Types.ObjectId,
ref: "User"
}
});
When I console.log(user), the terminal returns the following. I'm not too sure why it shows author[object] instead of its actual ID, maybe this is the problem?
{ posts:
[ { likes: [],
comments: [],
_id: 5aa3d0d806711d1483ae7e3e,
__v: 0,
author: [Object] },
{ likes: [],
comments: [],
_id: 5aa3cfc483622a145a86d618,
__v: 0,
author: [Object] },
{ likes: [],
comments: [],
_id: 5aa3cfbe83622a145a86d617,
__v: 0,
author: [Object] } ],
__v: 3}
EDIT 2
Weird enough, my other route which has the same structure (except its friendPosts) is working without any issue.
router.get("/home", function(req, res){
User
.findById(req.user._id)
.populate({
path: 'friendPosts',
populate: [{
path: 'author',
},
{
path: 'likes',
},
{
path: 'comments',
populate: [{
path: 'author'
}]
}]
})
.exec(function(err, currentUser){
res.render("main/home", {user: currentUser});
});
});

Answer 1

You need to try this:
const { ObjectId } = require('mongoose').Types;
router.get("/:id", function(req, res) {
const { id } = req.params;
User.findOne({ id: ObjectId(id)}).populate({
path: 'posts',
populate: [{
path: 'author',
},
{
path: 'likes',
},
{
path: 'comments',
populate: [{
path: 'author'
}]
}
]
}).exec(function(err, user) {
console.log(user);
res.render("profile");
});
});