I don't know why, but Trailhead does not see that I've setup a user Samantha Cordero with the profile Field Sales User. I've create the Field Sales User profile, created the user Samantha Cordero, activate the user, generate a password, and logged in as the user. I even logged in as her in Salesforce 1, but I still get this message:

Here is what her user detail page:

Field Sales User profile: