If your account is on lemmy.world... sucks to suck. Hurry up and wait. Maybe ping their admins in and see if the database just rekt your account in particular and maybe they can fix it, but don't expect a response. Don't rely on single huge instances to ever be stable, lemmy is still a fledgling beta software!

If you're using accounts from a different instance and are trying to interact with communities on lemmy.world, use different (ideally smaller) instances that may not be generating so much federation traffic and will have a better chance of getting through.

I dont know what that "account not ready" error specifically means, i just know that lemmy.world has been dying more often than not.