HELP WITH ERROR CODE '1004' Application-defined or object defined error

Hi guys I am doing a uni project and I am having problems with my VBA coding. I got help with the coding from ARowbot on here and he has really been a big help. However for some reason whenever I run my code although it still does what it is meant to do, i still get error code '1004' and it says 'Application-defined or object defined error'. I really do not know how to get rid of the error. the code is shown below

Sub InsulationSAVE()
Dim i, p As Integer
' InsulationSAVE Macro
Sheets("InsulationMonthly").Unprotect
For i = 5 To 16
    If Sheets("InsulationMONTHLY").Cells(4, i) = UCase(Format(Now, "mmm")) Then
        p = Sheets("INSULATION").Range("G" & Rows.Count).End(3).Row
        Sheets("INSULATION").Range("P5:P" & p).Copy
        Sheets("InsulationMONTHLY").Cells(5, i).PasteSpecial Paste:=xlPasteValues
        Application.CutCopyMode = False
        Sheets("INSULATION").Range("J5:N" & p).ClearContents
        Sheets("InsulationMONTHLY").Range(Cells(5, "E"), Cells(p, i)).Locked = True
        Sheets("InsulationMONTHLY").Protect
        Exit Sub
    End If
Next i
End Sub

I have attached the file here below..UNI (F) STOCK TAKE 2015 N M.xlsm

Thanks guys

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