Worksheet_Change function keeps crashing...why??

[biznez]

Hi, i have this code below and every time i make a change to the worksheet, Excel crashes. Whats the problem?

Private Sub Worksheet_Change(ByVal Target As Range)
Lastrow = Worksheets("Edit").Cells(Worksheets("Edit").Rows.Count, "A").End(xlUp).Row
SEQ = 1
For I = 2 To Lastrow
    If Cells(I, 6).Value = "GOOD" Or Cells(I, 6).Value = "BAD" Then
        Cells(I, 7).Value = SEQ
        SEQ = SEQ + 1
    Else: Cells(I, 7).Value = ""
    End If
   
Next I
End Sub