Acho que deu certo

ActiveSheet.Unprotect Password:="123"

Tem esta sugestão que vai facilitar. Coloque este código click 'ALT F11' e cole na planilha desejada para bloquear;

Private Sub Worksheet_Change(ByVal Target As Range) 'Código não bloqueia formula somente texto
Dim rng As Range
ActiveSheet.Unprotect Password:="12"
Cells.Locked = False
On Error Resume Next
Set rng = Cells.SpecialCells(XlCellTypeText)
Set rng = Cells.SpecialCells(xlCellTypeFormulas)
If Err.Number > 0 Then
Set rng = Cells.SpecialCells(xlCellTypeConstants)
Set rng = Union(rng, Cells.SpecialCells(XlCellTypeText))
Set rng = Union(rng, Cells.SpecialCells(xlCellTypeFormulas))
Else
End If
On Error GoTo 0
If Not rng Is Nothing Then rng.Locked = True
ActiveSheet.Protect Password:="12"
'ActiveWorkbook.Save
End
End Sub

Bloqueia texto e formulas