When trying to update to the latest firmware I got about 25% of the way through, and an error occurred. Retried, it started from 25%, but at around 75% another error occurred. However when it returned to the main menu I got the notification about miiverse and went to it. It fails to load but it turns out I'm still on 6.3. See the images for more info and better understanding.
http://imgur.com/a/zyZ92#0
http://imgur.com/a/zyZ92#0







