Synchronous XMLHttpRequest on the main thread is deprecated

Question

Why has this message suddenly started to appear in the Firefox console?

I'm using JQuery 1.7.1.

What in my app could I be doing that has caused this message to start appearing?

Answer 1

Using jQuery to append a script tag to the document will cause it to load the script with async:false and trigger this warning.

As in:

var script = $("<script></script>"); script.attr("src", player.basepath + "whatever.js"); $(document.body).append(script);