Macro formules ne rien faire en cas d'erreurs

Sub val1()
For i = 1 To Range("c5").End(xlDown).Row
  If InStr(Range("c" & i), "/") <> 0 Then
   Cells(i, 2) = Mid(Cells(i, 3), (Application.Search("/", Cells(i, 3)) + 2), 4)
  End If
Next
End Sub

Sub val()
Dim c As Range, p%
For Each c In Range("C5", [C5].End(xlDown))
  p = InStr(c, "/")
  If p Then
    c(1, -1) = Left(c, p - 1)
    c(1, 0) = Mid(c, p + 2, 4)
  Else
    c(1, -1).Resize(, 2).ClearContents
  End If
Next
End Sub

Sub val()
Dim c As Range, p%
For Each c In Range("C5", [C5].End(xlDown))
  p = InStr(c, "/")
  c(1, -1) = Left(c, IIf(p, p - 1, 0))
  c(1, 0) = Mid(c, p + 2, IIf(p, 4, 0))
Next
End Sub