I'm pretty sure you don't know how to apply Cross Domain origin.
Sometimes CocoonJS can't access to get files via AJAX due to CORS policy.
I made a php file which allows CORS to every places. I hosted it on my server.
Create a file
----------------------------------------------------------
<?php
header('Access-Control-Allow-Origin: *');
?>
Insert your a wall of text here
-----------------------------------------------------------
Then upload at your server, make a .capx, grab your php file from server and export to CocoonJS, it worked like a charm.
I hope it helps you, otherwise you need to give more explanation.