Wrong forum, please use the "Site" forum for those website related issues.
Moved there
I confirm, having the same bug with the "quick preview":
Uploading images does not work as it will call the Cloudflare "Huan" check website and once it get's back it calls
https://www.esoui.com/downloads/imagemgr.php without any of the needed POST/GET params that were there before. So yes, this is a bug.