This error in Flash
TypeError: Error #2007: Parameter child must be non-null
was caused by the fact that I had not dragged the progressbar component into my library just like a problem I had before posted at http://geek.michaelgrace.org/2009/11/1172-definition-fl-controlstilelist-could-not-be-found/
This is now the second time I have done this and hopefully the last. ; )
Goodbye Flash error “TypeError: Error #2007: Parameter child must be non-null” I don’t want to see you again!