Excel/VBA Worksheet_Change function running old version

What you’re experiencing is almost always not Excel showing a ghost old version, but rather some subtle issue with how the Worksheet_Change event is being triggered or where the code actually resides.

You can add a simple Debug.Print to confirm exactly which code is running:

Private Sub Worksheet_Change(ByVal Target As Range)
    Debug.Print "Worksheet_Change fired"
    MsgBox "Error B"
End Sub

If you see "Worksheet_Change fired", the code is being executed.

If you still see “Error: A”, then some other code or add-in is interfering.

Otherwise it would be helpful if the VBA code was included.