I went experimenting, what I discovered was that this option is only available if the current site is in a Trusted Zone. Adding the site as a Trusted Site solved the issue. It can be set the options in Internet Options
Tools>Internet Options>Security>Tusted Sites, Sites button, Add.
Refresh the page and the setting will kick in.
No whether you’re debugging your blog or the homepage for Morgan mouthpieces at WWBW, you should be able to test anything you’d like to test. Hope this helps!