I solved a mission a few days ago, but when I was going to publish it, it turned out that there's no auto-save feature, so my code was lost and I was unable to publish my solution. Now I did nothing in-between clicking solve and publish, so that was really annoying and unexpected. It should either autosave or ask if I want to save it.

Also, please don't ask for feedback in an email without providing a reply-email or a link to a contact form (or in this case, a forum).