@DanGetz yeah that was the ChatExchange problems, which thanks to @JohnB a rapid fix to the new page code was put in that 'restored' the entry points at which ChatExchange under the hood uses to start the login / auth process and such
and for rapid-fixing things too (especially you @JohnB for poking the new UI to 'match' a little like the original system used at least to enter the login/process flows)
thank you to @JohnB and @Emerson and the vast number of other SE staff who have been dragged into this hell JUST from this here incident with Smokey who responded and are looking to see how we can improve things going forward :D
which means that in the next 2 hours there's only a few solutions: revert changes in Chat, or SE has to help us fix CE to adapt to the new environment. (or 3: they adjust the new stuff to add the things that CE is looking for to get into the login flows)
We are aware that SmokeDetector is not working, the fault lies with the changes to the Chat UI and frontend which SmokeDetector is dependent on, which means SD can't login.