"Not Authorised" is an error message displayed when the session is disconnected.
Sessions are disconnected for the following reasons.
- Session expiration period has expired
- Connection limit per account has been exceeded
- Device in use has been deleted
To resolve this, re-login.
For information about session expiration periods, connection limits per account, and device deletion, see the following.
Related:
What is Session Management?
How many devices can I use at the same time with the same account?
Temporarily Suspending or Deleting Access from Any Device (Web Browser)