I had a conflict with BuddyPress's avatar crop which used Jcrop.js, a jQuery image cropping utility. The error generated in Chrome's console looked like this:

Uncaught TypeError: i.Jcrop is not a function

I wasn't using the loader anymore, so I just commented it out. From research, this type of error commonly occurred when jQuery was loaded twice or Jcrop.js was loaded before jQuery - neither of which applied in my case, but if others come across a similar issue, this might guide you toward troubleshooting. I don't know protocol with GitHub issues, but I wanted to leave a breadcrumb in case anyone else had a similar problem and this came up in Google. A post like this would have saved me most of the morning.... :o/