Not every slide has a Subtitle placeholder, even if it looks like a subtitle
1. Is that a true placeholder type Subtitle, or a text box that you're using as a subtitle
2. Could you use the Master Slide(s) to format the way you want?
3. Little rearranging and one add
Option Explicit
Sub Titles()
Dim oSld As Slide, oShp As Shape
For Each oSld In ActivePresentation.Slides
For Each oShp In oSld.Shapes
With oShp
If .Type = msoPlaceholder Then
Select Case .PlaceholderFormat.Type
Case ppPlaceholderTitle, ppPlaceholderCenterTitle ' <<<<<<<<<<<<<<
.Top = 5
.Left = 5
.TextFrame.TextRange.Font.Name = "Times New Roman"
.TextFrame.TextRange.Font.Size = 24
Case ppPlaceholderSubtitle
.Top = 10
.Left = 10
.TextFrame.TextRange.Font.Name = "Times New Roman"
.TextFrame.TextRange.Font.Size = 18
End Select
End If
End With
Next oShp
Next oSld
End Sub