Code is Bombing 4 lines from bottom;
How can I alter to fix?

Sub FillInBlanks()
Dim Rng1 As Range, Rng2 As Range
Dim RngArea As Range
If Selection.Columns.Count 1 Then
MsgBox "You can Only Select 1 Column at a time"
Exit Sub
End If
Set Rng1 = Selection
Set Rng2 = Rng1.SpecialCells(xlCellTypeBlanks)
Rng2.FormulaR1C1 = "=R[-1]C"
With Rng2
.Copy
.PasteSpecial xlPasteValues ' R/T 1004 - CANNOT BE USED ON MULTIPLE
SELECTIONS
End With
Application.CutCopyMode = False
End Sub