Черный экран при выполнение макроса

For i = 1 to iLastRow
   DoEvents
   ' ...код
Next

T = Timer
For i = 1 To 1000000
    x = x + 1
Next i
Debug.Print "Без  DoEvents: " & Timer - T
 
T = Timer
For i = 1 To 1000000
    If i Mod 100 = 0 Then DoEvents
    n = n + 1
Next i
Debug.Print "C условием : " & Timer - T
 
T = Timer
For i = 1 To 1000000
    DoEvents
    m1 = m1 + 1
Next i
Debug.Print "Без условия : " & Timer - T

Sub TestTime()
   Dim i As Long, k As Long, n As Long, m As Long, _
       t1 As Single, t2 As Single, t3 As Single, t4 As Single, t5 As Single, t6 As Single
 
   t1 = Timer
   n = 0
   For i = 1 To 1000000
      n = n + 1
   Next
   t2 = Timer
   
   t3 = Timer
   m = 0
   For i = 1 To 1000000
      DoEvents
      m = m + 1
   Next
   t4 = Timer
 
   t5 = Timer
   k = 0
   For i = 1 To 1000000
      If i Mod 1000 = 0 Then DoEvents
      k = k + 1
   Next
   t6 = Timer
 
   MsgBox "Без DoEvents = " & t2 - t1 & ", с DoEvents = " & t4 - t3 & ", с DoEvents/1000 = " & t6 - t5
   '  0.0078125
   ' 13.5625
   '  0.0390625
End Sub