Code:
Sub STEP6()
    Dim Ws1 As Worksheet, Ws2 As Worksheet
    Dim Wb1 As Workbook, Wb2 As Workbook
    Dim r2&, lr&, i&
    
    Set Wb1 = Workbooks.Open("C:\Users\WolfieeeStyle\Desktop\1.xls")
    Set Ws1 = Wb1.Worksheets.Item(1)
    Set Wb2 = Workbooks.Open("C:\Users\WolfieeeStyle\Desktop\Files\AlertCodes.xlsx")
    Set Ws2 = Wb2.Worksheets.Item(4)
    With Ws1
        lr = .Cells(.Rows.Count, "I").End(xlUp).Row
        For i = 2 To lr
            ' Reset r2
            r2 = 0
            ' Avoid error messages
            On Error Resume Next
            ' Try to get r2
            r2 = WorksheetFunction.Match(.Cells(i, "I"), Ws2.[B:B], 0)
            ' Restore error handling
            On Error GoTo 0
            ' Only set column K if r2 is valid
            If r2 > 0 Then
                If Ws2.Cells(r2, "D") = ">" Then
                    .Cells(i, "K").Value = Ws2.Cells(i, "E").Value - 0.01 * Ws2.Cells(i, "E").Value
                Else
                    .Cells(i, "K").Value = Ws2.Cells(i, "E").Value + 0.01 * Ws2.Cells(i, "E").Value
                End If
           End If
        Next i
    End With
    Wb1.Save
    Wb1.Close
    Wb2.Close
    
End Sub