That was because SteemConnect was down. They were using the same RPC node IIRC, when we should have apps using different API endpoints ideally.
SteemConnect is used to make a transaction which grants an application the authority to make posts on your behalf. If it's down, Busy won't work until it's back or it finds another way to let you post (either use another app to create the account-update transaction which modifies your account authority settings or start letting you use your private keys on the site).
If you have granted the authority before, there's no need to wait on SteemConnect.