Run time error 1004
 

I have my workbook shared...and have been getting a Run
Time Error 1004. I've been trying to narrow down what is
causing it in my code and it appears that it is something
with the code below:

Private Sub Workbook_BeforeClose(Cancel As Boolean)
ActiveSheet.Protect DrawingObjects:=True, Contents:=True,
Scenarios:=True
End Sub

I understand sharing a workbook can make things a bit
finicky...but what am I doing wrong here?