This is in BLB?
To override a method you have to use the exact method signature defined by the base class.
Visual Studio will help you get this right if you just type "override" and hit the spacebar - you'll get a list of possible overrides, and if you select the right one VS will create the empty method for you.
Child_Update() looks like this:
protected virtual void Child_Update(params object[] parameters)
So your override must match that signature.
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