Hello,
I have the same problem. The response of the media-upload.php is the following. I see no js errors in console.
Wordpress version: 3.9.2
Plugin version: 1.0 (Same problem with a previous version)
<script type="text/javascript">
/* <![CDATA[ */
var win = window.dialogArguments || opener || parent || top;
win.send_to_editor('<img data-id=\"409\" src=\"https://www.mydomain.gr/wp-content/uploads/photo1.jpg\" alt=\"Alt\" width=\"824\" height=\"549\" class=\"alignnone size-full wp-image-409\" />');
/* ]]> */
</script>
Thank you