Well i got this same issue but for me it isn’t solved.
"NetworkError: 404 Not Found - https://www.***.nl/wp/home/augus/sites/***/www/content/plugins/custom-sidebars/inc/external/wpmu-lib/css/wpmu-ui.css?ver=3.9.1"
Here you can see that with v 2.0.3 i still get the same issue.
The problem is my plugin folder is in /root/content/plugins/ while the way the script is now its looking in /root/wp/home/augus/sites/***/www/content/plugins.
So a simple path error.