If you've been trying to login to Twitter's Developers site, dev.twitter.com, but have been locked out, it's possible that you might have two-factor authentication (or, as Twitter calls it, login verification) turned on.
If that's true, you simply need to generate a temporary password to login to the site.
It's surprising that the mobile apps are so helpful in telling you that you need to use a temporary password when two-factor authentication is turned on. The Developer zone just says it can't log you in. I hope they fix this soon.