Referencing Worksheet Named Range from a Module

Hello

I can't get this snippet of test code to run. I'm referencing the range as I've seen on msdn with no luck. I get a 1004 "Application-defined or object-defined error". Help?

Sub NewButton_Click()

Dim rng As Range
With ActiveWorkbook.Worksheets("categories")
rng = .Range("category")
End With

For Each c In rng
MsgBox c.Value
Next

End Sub