Similar to what @mirkolofio describes, on our site with the new version of “Enable jQuery Migration Helper” (1.1.0), when logged in as a WP admin and viewing site pages showing the admin bar across the top, the deprecation-notice.js file is running and throwing an error indicating jQuery.migrateWarnings is undefined. From what I can see, the file where jQuery.migrateWarnings gets defined (jquery-migrate-1.4.1-wp.js) isn’t loaded when we’re viewing non-admin area pages while logged in.
