Fix it
A learner cannot sign in
In short
Check the email, the password, the academy address, Google sign-in and other devices.
A learner says they cannot get in. Check these, most likely first.
Still stuck? Look for the invite or reset email in the Outbox, and read Emails are not arriving: checklist.
The email: search for the learner in Users by email. No result means no account yet. Add them with Add Student, or tell them to sign up.
The password: "Invalid email or password." means a wrong email or password. They can use Forgot password. After several wrong tries, sign-in pauses for a short while.
The address: "This account cannot sign in to this academy" means they have no account here. Check they are on your academy's address, or invite them.
Google: "We could not sign you in with Google here" means that Google account belongs to another academy. They can log in with email and password instead.
Another device: if you restrict parallel logins, a new sign-in signs the old one out with "You were signed out because this account signed in from another device or browser."
Sign-ups closed: "This academy isn't taking new sign-ups right now" means self sign-up is off. Add the learner yourself.