Kernel with CodeMirror simpleMode defined, not surviving refresh

Hi there guys,

I wrote a kernel with syntax highlighting built-in. It works great! I load it up, and everything highlights with the colors I gave it. The issue though is that the syntax highlighting doesn’t work when I refresh the page. I don’t know what I’m doing wrong, as I can’t find any help information on this.

Here’s what I have for the kernel.js file

define(
['codemirror/lib/codemirror', 'codemirror/addon/mode/simple'],
function(CodeMirror) {
  return {
    onload: function(){
        CodeMirror.defineSimpleMode('<name_of_langauge>', {
        /* definitions here */
       }
    }
   }
}

I am seeing in the console the 404 message:
http://localhost:8888/static/components/codemirror/mode/<name_of_language/<name_of_language.js>?v=…
But I get this on the first load as well (I don’t understand why it’s trying to load that, either.

Any insight is appreciated.