Hello, we had some partial downtime today that was preventing game uploads from being saved. The issue has been resolved and we've made some changes to make sure it can't happen again. Sorry for the trouble. Tell me if you are still experiencing any issues. Thanks
It sounds like you've packaged the game wrong. I found this tutorial here that might be helpful: http://wiki.compilgames.net/doku.php/gdevelop5/publishing/html5_game_in_a_local_folder
Edit: I see you're using a 7zip file (7z). You must use zip (.zip), no other archive format is supported right now. Thanks