# 5000: The class 'CustomLoader' must subclass 'flash.display.MovieClip'

**URL:** <https://forum.kirupa.com/t/5000-the-class-customloader-must-subclass-flash-display-movieclip/325724>\
**Category:** flash\
**Created:** [November 1, 2011, 9:47pm UTC](https://forum.kirupa.com/t/5000-the-class-customloader-must-subclass-flash-display-movieclip/325724 "2011-11-01T21:47:15Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![dbaseivom](https://avatars.discourse-cdn.com/v4/letter/d/9de0a6/32.png) [@dbaseivom](https://forum.kirupa.com/u/dbaseivom)\
**Post date:** [November 1, 2011, 9:47pm UTC](https://forum.kirupa.com/t/5000-the-class-customloader-must-subclass-flash-display-movieclip/325724/1 "2011-11-01T21:47:15Z")

</div>

5000: The class ‘CustomLoader’ must subclass ‘flash.display.MovieClip’ since it is linked to a library symbol of that type.

This is the error I get when I try to run my flash project.

I followed this tutorial  
[http://broskies.net/temp/tut.html](http://broskies.net/temp/tut.html)

but I use Flash CS4 instead of FlashDeveloper.

I googled about this problem, but havn’t find a working solution… perhaps am I doing something wrong?

What I´ve done in an attempt to fix the error is that I:

1. Added

```auto
import flash.display.MovieClip;

```

to CustomLoader.as

1. Added a Base class to intro3D.fla. The settings can be seen in this image:  
[http://broskies.net/temp/Image1.png](http://broskies.net/temp/Image1.png)

Help is very appreciated!