Some times, when you try to load content into a fancybox, you may get this message : 

“the requested content cannot be loaded. please try again later.”

$.fancybox({
'width': '100%',
'height': '100%',
'autoScale': true,
'transitionIn': 'fade',
'transitionOut': 'fade',
'type': 'inline',
'content': $("#results").html(),
});

In my case, this hapenned when I tried to load content in ajax from an html element,  whose value wasn’t set yet. To fix that, I added a timer to wait for the results.