Favicon not being placed

I’ve uploaded the favicon to the Media Library but I’m not able to place it in the plugin input field using ‘Insert into Post’ button.

I can override the functionality by copying the full URL for the uploaded favicon and placing it in the input field but it doesn’t accept relative paths (just absolute).

Using the above technique works for .png icons but not for .ico files.

http://ww.wp.xz.cn/extend/plugins/blog-icons/