Virtualscroll; null after livereload

Everytime I made a change in my Ionic 3 app it reload and enter to HomePage. HomePage has the following content:

  <div [virtualScroll]="categories" approxItemHeight="220px">
    <div *virtualItem="let category">
      <div class="virtual-padding">

  <ion-infinite-scroll (ionInfinite)="$event.waitFor(moreCategories($event))">

and when livereload finish loading I got the following error:

Uncaught TypeError: Cannot set property 'length' of null
    at VirtualScroll.readUpdate (vendor.js:76860)
    at vendor.js:76710
    at SafeSubscriber.schedulerFn [as _next] (vendor.js:4222)
    at SafeSubscriber.__tryOrUnsub (vendor.js:28091)
    at (vendor.js:28038)
    at Subscriber._next (vendor.js:27978)
    at (vendor.js:27942)
    at (vendor.js:36646)
    at EventEmitter.emit (vendor.js:4196)
    at Array.<anonymous> (vendor.js:35791)

I have to reload the page, but it is so annoying. What is the case of livereload if I have to reload the page manually?

Ionic info:

cli packages: (.../aide/node_modules)

    @ionic/cli-utils  : 1.9.2
    ionic (Ionic CLI) : 3.9.2

global packages:

    Cordova CLI : 7.0.1

local packages:

    @ionic/app-scripts : 2.1.3
    Cordova Platforms  : android 6.2.3
    Ionic Framework    : ionic-angular 3.6.0


    Android SDK Tools : 26.0.2
    Node              : v8.4.0
    npm               : 5.3.0
    OS                : Linux 4.10

Ionic lab reported info:

Ionic Framework: ^3.6.0
Ionic App Scripts: 2.1.3
Angular Core: 4.1.3
Angular Compiler CLI: 4.1.3
Node: 8.4.0
OS Platform: Linux 4.10
Navigator Platform: Linux x86_64
User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.113 Safari/537.36