Despite being an administrator on my system the security settings would not aallow me save the changes from notepad into the correct folder. I had to save the changes to a separate folder and hen copy the file to the correct location after right clicking and opening Windows Explorer as an administrator.
If you are editing with notepad, you may have to right click and run it as Administrator. You may be an admin but notepad is not elevated by default.
I ran into the same issue.