Sitecore 8.2, we have an item template featuring an image field. The preferred workflow for creating an instance of this template is the use of the Browse trigger on the image field and the Upload dialogs in the ensuing displays.
A problem has arisen where this goes fine until the user clicks the final Upload link/button, at which point, in certain environments, nothing happens; that is, it sits indefinitely at 0%. Developer tools indicate
uploader.js (line 440) is throwing an error trying to retrieve the anti-forgery token because
_sc.Helpers.antiForgery is undefined. This is at the end of a fairly deep chain of Sitecore and jQuery invocations. Is it a known and understood problem? Or, more to the point, is it anything I can address?