My boss added some custom CSS to styleLibrary/themable and insists those are the only changes made. However, I cannot figure out where all of these errors are coming from:

I clicked on the "home.aspx:546" error and it showed the following:

I searched the master page for anything out of the ordinary, and nothing.
The files he added (simply custom CSS files from some company) are:

Any ideas where the errors are coming from? I realize the ajax and bootstrap CDN URLs are incorrect, but I am not sure where they are to change them. The error happens on every page in the collection