Chrome extension using ibox popup

Question

I am trying to make a popup appear using the iBox javascript. When I tested on my machine using a simple html (called "test.html"), it worked fine. However, when I used the same call in my Chrome extension

document.addEventListener('keydown', function(e){
 if (e.keyCode == 81 && e.altKey && !e.shiftKey && e.ctrlKey) {
  iBox.showURL('search.html');
 }
}, false);

I receive this error

There was an error loading the document.

Has anyone received this error or knows what to do in this case?