Laufzeitfehler 1004

Public Function Letzte(ByVal TabBlatt As Worksheet, Optional ByVal Spalte As Integer = 1,  _
Optional ByVal StartZeile As Integer = 1) As Long
Dim Zeile As Long
On Error GoTo Fehler
Zeile = StartZeile
With TabBlatt
Do While (.Cells(Zeile, Spalte).Value  "")
Zeile = Zeile + 1
Loop
End With
Letzte = Zeile - 1
Exit Function
Fehler:
MsgBox "Laufzeitsfehler " & Err.Number & ". " & Err.Description
End Function