I have a salesforce account - daniel.wymer@teradata.com - and get into endless loop and cannot reach Trailhead.  It seems like I have a Salesforce account, have established a password, but cannot login to Trailhead.

I have a new user who is trying to go through Trailhead, but every time he tries to connect his Dev Org (i have verified that it is indeed a dev org and not one of our production orgs or our sandboxes) he gets an error sayign he must log in with a developer org. He's tried restarting his browser, restarting his computer and nothing is making a difference.

It allows him to log in, and I can see it going to the na instance where his dev org "resides" but then it says it's not a dev org. Any ideas?