Mongoose Error on .insertMany()

I’ve looked everywhere and I cannot figure out why I get this error while I try to create and save multiple documents with Mongoose.

It is working to save individual documents, but when I run the script to add multiple documents with .insertMany() I get the following message in terminal and I have no clue what to do with it.

        for (let i = 0; i < error.writeErrors.length; ++i) {

TypeError: Cannot read properties of undefined (reading 'length')
    at /Users/FruitsProjectMongoose/node_modules/mongoose/lib/model.js:3519:47
    at collectionOperationCallback (/Users/FruitsProjectMongoose/node_modules/mongoose/lib/drivers/node-mongodb-native/collection.js:194:24)
    at /Users/FruitsProjectMongoose/node_modules/mongodb/lib/utils.js:349:66
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)

It would be an understatement to say that I have tried everything that I could think of/find across the web. I’ve messaged a few devs. and they’ve recommended me to try some things but no luck. I really need some help with this. I start to think it might be something wrong with my system.

I’ve installed MongoDB through HomeBrew and Mongoose through npm in the past two days so everything is up-to-date.

Here is my simple JS script:

const mongoose = require("mongoose");
mongoose.set('strictQuery', false);

// Connect to MongoDB by port and catch errors.
main().catch(err => console.log(err));

async function main() {
    await mongoose.connect('mongodb://')
    .then(() => console.log('Connected!'));

    // Defining a Model Schema.
    const Schema = mongoose.Schema;
    const fruitSchema = new Schema({
        name: {
            type: String,
            require: true
        rating: {
            type: Number,
            require: true
        review: {
            type: String,
            require: true

    const peopleSchema = new Schema({
        name: String,
        age: Number

    // Create a Model.
    const Fruit = new mongoose.model("Fruit", fruitSchema);
    const People = new mongoose.model("People", peopleSchema);

    // Create & Save a Document.
    const fruit = new Fruit({
        name: "Banana",
        rating: 10,
        review: "Perfection!"
    // await;

    const people = new People({
        name: "Eduard",
        age: 25
    // await;

    // Create & Save docs. in Bulk.
    const kiwi = new Fruit({
        name: "Kiwi",
        rating: 9,
        review: "Great, kinda expensive!"
    const orange = new Fruit({
        name: "Orange",
        rating: 6,
        review: "Too sweet."

    const apple = new Fruit({
        name: "Apple",
        rating: 7,
        review: "Great fruit!"

    Fruit.insertMany([kiwi, orange, apple], function(err) {
        if (err) {
        } else {
            console.log("Succesfully saved to fruitsDB");


MongoDB server is running on brew services start mongodb-community .