There seems to be some major server issues as well so it may take some time to resolve the main issue.
If you are having issues logging into chat since new upgrade with an IPad here are some steps to follow.
IPAD USERS: settings> left side down to safari> right side down to advanced> right side website data> clear all web site data. Restart safari log back into DU. Click chat> icon should now be there to start chat.
There seems to be some major server issues as well so it may take some time to resolve the main issue.