How store and retrieve object

Hi i am trying to store object to my mobile file system, by creating a file and read or overwrite that file when needed i could able to create file or folder using cordova file plugin. but when i try to create a file with .txt extension i get err in my console "resources interrupted as script but started as MIME type text/plane ". if i remove .txt extension file gets created.
What i need is to create a file that has the user data and store it to mobile filesystem could someone help me

import { Component } from '@angular/core';
import { NavController, NavParams } from 'ionic-angular';
import { File } from 'ionic-native';

declare var cordova: any;

@Component({
  selector: 'page-login',
  templateUrl: 'login.html'
})
export class LoginPage {

    user =  {
                Name: '',
                email: '',
                phone: '',
                Country: ''        
            };
     

    constructor(public navCtrl: NavController, public navParams: NavParams) {}

    Upload(){
        console.log("upload button clicked",this.text);
    }

    create(){
        console.log("create");
        File.createFile(cordova.file.externalRootDirectory  , "file.txt", true)
                .then(function (success) {
                // success
                console.log("folder created", success);
                }, function (error) {
                // error
                    console.log("folder not created", error)
            });
    }


    writeFile(){
        console.log("write to file");


    var root = cordova.file.externalRootDirectory;
        var path = root + "/myFolder"
        var text = JSON.stringify(this.user);

           File.writeFile(path  , "file.txt",  "text", true)
                .then(function (success) {
                    // success
                    console.log("folder created", success);

                }, function (error) {
                    // error
                    console.log("folder not created", error)
            });   

    }
}

Is there a reason you’re not using something like ionic-storage for this?