Apply To All Sheets Not Working

why the "apply to all worksheets" portion of this code is not working? I appreciate your time.

Sub Delete_0activityaccount()
'
'
Dim mywSheet As Excel.Worksheet
For Each mywSheet In ActiveWorkbook.Worksheets

lastrow = Cells(Rows.Count, 1).End(xlUp).Row
For i = lastrow To 8 Step -1
If Cells(i, 4).Value = 0 And Cells(i, 5).Value = 0 And Cells(i, 6).Value = 0 And Cells(i, 7).Value = 0 And Cells(i, 8).Value = 0 _
And Cells(i, 9).Value = 0 And Cells(i, 10).Value = 0 And Cells(i, 11).Value = 0 And Cells(i, 12).Value = 0 _
And Cells(i, 13).Value = 0 And Cells(i, 14).Value = 0 And Cells(i, 15).Value = 0 And Cells(i, 16).Value = 0 _
And Cells(i, 17).Value = 0 And Cells(i, 18).Value = 0 Then
Rows(i).Delete
Else
End If
Next i

Next mywSheet

End Sub