It is Kiwi, not goatchat. Unless you can figure out the dreaded password boxes, you'll have to wait until Kiwi fixes itself.
Or you could try connecting with another server.
https://kiwiirc.com/client/kappa.hira.io:+6697#throat
https://kiwiirc.com/client/eddie.goat.chat:+6697#throat
I'm getting the same error as you on all goatchat servers using kiwi.
Edit: Freenode works fine, looks like its just goatchat that is fucked on kiwi.