Unprotect active sheet

[BravoBravoAu]

Based on some earlier advice from @Yongle, I've been using a worksheet to track progress on tasks, using the code below to record date, time and by who certain entries are made:

Private Sub Worksheet_Change(ByVal Target As Range)
    If Target.Row = 1 Then Exit Sub   'ignore changes in header row
   
    If Target.Column = Range("K1").Column Then
        Cells(Target.Row, "L") = Date
        Cells(Target.Row, "M") = Time
        Cells(Target.Row, "N") = Application.UserName
    End If
   
 If Target.Column = Range("R1").Column Then
        Cells(Target.Row, "S") = Date
        Cells(Target.Row, "T") = Time
        Cells(Target.Row, "U") = Application.UserName
    End If
    
If Target.Column = Range("V1").Column Then
        Cells(Target.Row, "W") = Date
        Cells(Target.Row, "X") = Time
        Cells(Target.Row, "Y") = Application.UserName
    End If
    
End Sub

I'm now looking to protect the worksheet as it will be shared and some fields don't need most users to have access to them.

To do so, I expected I would have to modify each of the three above ranges to:

If Target.Column = Range("K1").Column Then
        ActiveSheet.Unprotect "PASSWORDHERE"
        Cells(Target.Row, "L") = Date
        Cells(Target.Row, "M") = Time
        Cells(Target.Row, "N") = Application.UserName
        ActiveSheet.Protect "PASSWORDHERE", True, True
    End If

But I'm continuing to get "run-time error 1004". When I debug, the first line (date) is highlighted.

HELP?

 

[My Aswer Is This]

Here is how you can do what you want.

You can modify this and add in the Password and UserName

You should be able to see the logic

Private Sub Worksheet_Change(ByVal Target As Range)
'Modified  10/4/2018  1:16:02 AM  EDT
If Target.Column = 11 Then
    Target.Offset(, 1).Value = Date
    Target.Offset(, 2).Value = Time
End If
End Sub