# Parameter child must be non null?

**URL:** <https://forum.kirupa.com/t/parameter-child-must-be-non-null/276416>\
**Category:** flash\
**Created:** [November 26, 2008, 10:58pm UTC](https://forum.kirupa.com/t/parameter-child-must-be-non-null/276416 "2008-11-26T22:58:17Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Katie\_Lee](https://avatars.discourse-cdn.com/v4/letter/k/35a633/32.png) [@Katie\_Lee](https://forum.kirupa.com/u/Katie_Lee)\
**Post date:** [November 26, 2008, 10:58pm UTC](https://forum.kirupa.com/t/parameter-child-must-be-non-null/276416/1 "2008-11-26T22:58:17Z")

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Hi,

Do you know what Parameter child must be non-null means?  
at flash.display::DisplayObjectContainer/addChild()

I am trying to add a picture (picture\_mc) from the previous frame, into person\_mc.

person\_mc.addChild(picture\_mc);