We have a chatter free user whose profile is also Single Sign-On enabled. When the user tries logging in to Trailhead, he gets Single Sing-on login error but when he logs in via Sing Sign-On he can only access Salesforce.
Has anyone had this issue? If so, how did you solve it?
On
Wait your user is on a Production Org and you want the same user to be able to login to Tralhead with the same username and password (using SSO)?
If so, that will not work, trailhead and Salesforce Org Logins are completely diferent things, you need to create a user on Trailhead in order to login to the platform. Or an employer may create and manage your account.
You can link a training org (or a developer org used for training) on the Hands On Orgs section.
Read more about it on https://trailblazer.me/resource/documents/documents/pdf/TermsOfUse_en_US.pdf Chapter 4
Try the following: Log in with your normal credentials into the Trailhead platform. Than go to your user settings -> Settings -> down to 'Salesforce Login' section. There you can set an account.