I've recently noticed, that users are no longer able to update banners on my site, and I see the error "Uncaught ReferenceError: glUploader_yh4sfuZ8_bx_persons_cover_crop is not defined"
I have tried clearing the cache (Client and App) and checking for updated but still get the same issue.
UPDATE: due to our cooperate investigation we foudn that was a Cloudflare feature called Rocket Loader. (See https://developers.cloudflare.com/speed/optimization/content/rocket-loader)
Disabling Rocket Loader from my Cloudflare account looks to have resolved this issue