As someone who has fiddled around with the Beta phase, it seems like not much is done when it comes to error handling and/or telling the user that a server-side error has happened. Multiple examples:

• You weren't able to post forum replies with a lot of characters and no "too many characters" error was shown.
• Transferring ownership without selecting a role to keep yourself as sends the notification but doesn't actually let the target user accept your ownership request.

These errors however do pop up if you open up the developer console.

Please make it clear why the website seems to not work as intended when the user isn't doing something right. I understand that v3 is in it's infancy, although something like this is rather critical I'd say.