I want that is the statement is true, give me a message and stop the macro,
if cell Ki is empty. If the cell contain data I would like to continue with
the macro. But when I run the macro for test, if the cell contain data gave
me the message and top the macro. What is wrong?

For i = 1 To nLastRow + 1 - nFirstRow
If Trim(wsSystem.Cells(i, 11)) = "" Or IsEmpty(wsSystem.Cells(i,
11)) Or IsNull(wsSystem.Cells(i, 11)) Then
MsgBox "You do not indicated if the System need a Critical or
Non-Critical Overall Assessment"
Exit Sub
End If
Next i