Modify multiple excel files - No mistakes, no results - excel

Question

I just need to change the contents of two cells, as you can see, to all the files in a certain folder but nothing happens when the script starts. No mistakes, no results.
Sub ModifyAllFiles()
On Error Resume Next
MyPath = "Macintosh HD:Users:Danespola:Desktop:test"
If MyPath = "" Then Exit Sub
On Error GoTo 0
If Right(MyPath, 1) <> Application.PathSeparator Then
MyPath = MyPath & Application.PathSeparator
End If
FilesInPath = Dir(MyPath, MacID("XLSX"))
If FilesInPath = "" Then
MsgBox "No files found"
Exit Sub
End If
Fnum = 0
Do While FilesInPath <> ""
Fnum = Fnum + 1
ReDim Preserve MyFiles(1 To Fnum)
MyFiles(Fnum) = FilesInPath
FilesInPath = Dir()
Loop
If Fnum > 0 Then
Do While Filename <> ""
Application.ScreenUpdating = False
Workbooks(FilesInPath).Open
Range("A5").Value = "ca1"
Range("A6").Value = "ca2"
Workbooks(FilesInPath).Save
Workbooks(FilesInPath).Close
Filename = Dir()
Loop
Application.ScreenUpdating = True
End If
End Sub
Thanks!

Answer 1

No need to count the files or build an array just update them as they are found.
Sub ModifyAllFiles()
Dim Filename As String, MyPath As String, count As Integer
Dim wb As Workbook, t0 As Single
t0 = Timer
MyPath = "Macintosh HD:Users:Danespola:Desktop:test"
If Right(MyPath, 1) <> Application.PathSeparator Then
MyPath = MyPath & Application.PathSeparator
End If
' this may not work for excel files created with windows
'Filename = Dir(MyPath, MacID("XLSX"))
Filename = Dir(MyPath)
If Filename = "" Then
MsgBox "No files found"
Exit Sub
Else
Application.ScreenUpdating = False
Do While Filename <> ""
If LCase(Right(Filename, 5)) = ".xlsx" Then
count = count + 1
Set wb = Workbooks.Open(MyPath & Filename)
With wb.Sheets(1)
.Range("A5").Value = "ca1"
.Range("A6").Value = "ca2"
End With
wb.Save
wb.Close
End If
Filename = Dir()
Loop
Application.ScreenUpdating = True
End If
MsgBox count & " files updated", vbInformation, "Finished in " & Int(Timer - t0) & " secs"
End Sub