# Failing to use my movie clip in flex builder

**URL:** <https://forum.kirupa.com/t/failing-to-use-my-movie-clip-in-flex-builder/225546>\
**Category:** flash\
**Created:** [May 13, 2007, 4:07pm UTC](https://forum.kirupa.com/t/failing-to-use-my-movie-clip-in-flex-builder/225546 "2007-05-13T16:07:42Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![devboy](https://avatars.discourse-cdn.com/v4/letter/d/a587f6/32.png) [@devboy](https://forum.kirupa.com/u/devboy)\
**Post date:** [May 13, 2007, 4:07pm UTC](https://forum.kirupa.com/t/failing-to-use-my-movie-clip-in-flex-builder/225546/1 "2007-05-13T16:07:42Z")

</div>

I’m creating a MovieClip in CS3 with a button component, expose the button to code with an instance name and export it as a swc file.  
I then import that .swc into a flex project and display an instance of the movie clip. It throws this:  
TypeError: Error #2007: Parameter child must be non-null.  
at flash.display::DisplayObjectContainer/addChildAt()  
at fl.controls::BaseButton/fl.controls:BaseButton::drawBackground()  
at fl.controls::LabelButton/fl.controls:LabelButton::draw()  
at fl.controls::Button/fl.controls:Button::draw()  
at fl.core::UIComponent/fl.core:UIComponent::callLaterDispatcher()

If I remove the button instance name from the MovieClip the error stops but then the movie clip just loops endlessly showing the button assets.

Anyone got any idea why?