Open excel file from powerpoint via vba throws error 32809

When trying to open an Excel file from Powerpoint via vba, it has started  throwing an error 32809. Its been working fine , and it's only a select Group of machines that gives the error - on other test machines it Works as usual. All machines running  Win7 / Office 2010

Sub OpenFile()
    Dim strxlsFil As String
    Dim objXL As Object
    Dim boolXL As Boolean
    Dim objActiveWkb As Object
   
    strxlsFil = ActivePresentation.Path & "\MyFile.xlsm"
   
    If Dir(strxlsFil) = "" Then
        MsgBox "The indicated Excel file (" & strxlsFil & ") could not be located", vbCritical
        Exit Sub
    End If
       
    Set objXL = CreateObject("Excel.Application")
    objXL.Application.Workbooks.Open strxlsFil
    objXL.Application.screenupdating = False
    Set objActiveWkb = objXL.Application.ActiveWorkbook
    objXL.Visible = True
    objActiveWkb.Worksheets("Order").UnProtect  <- this is where the error is shown