The following runs fine when run from within Word. What line of your code is throwing the error?
Code:
Sub Textbox()
Dim wdApp As Word.Application
Dim wdDoc As Word.Document
Dim wdShp As Word.Shape
'Set wdApp = CreateObject("Word.Application")
With Application
.Visible = True
.ScreenUpdating = False
Set wdDoc = .Documents.Add
Set wdShp = wdDoc.Shapes.AddTextbox(Orientation:=msoTextOrientationVertical, Left:=10, Top:=10, Width:=70, Height:=200)
With wdShp.TextFrame
.TextRange = "MEMO"
.TextRange.Font.Name = "Arial"
.TextRange.Font.Size = "48"
End With
.ScreenUpdating = True
End With
Set wdDoc = Nothing: Set wdShp = Nothing
End Sub