We are currently experiencing some login instabilities via GitHub. Following an incident earlier this week, a temporary safety limit was kept in place to protect the connection, which is currently restricting access for some users.

Our team is progressively lifting this restriction to get everyone back online.

In the meantime, you have two options:

Wait a few minutes and try logging in again.
Bypass GitHub by accessing your database directly via yourdbname.odoo.com/web/login

Any ETA for this?