Controlling settings, permissions, and membership within Teams and channels
The most likely cause is that the account is no longer recognized as part of the class team and is now being treated as an external/guest user, so Teams is asking for a code or blocking access.
Because this is an education/class scenario, only the school’s IT admin or the class owner (teacher) can fix it. Steps they need to take:
- Verify the correct account
- Make sure the sign‑in is with the school/work account, not a personal Microsoft account. If the wrong account is signed in, sign out and sign back in with the school account.
- If signed in to Teams Free with a personal account, switch/add the school account as described in “Signed in to the wrong account in Microsoft Teams Free”.
- Have the school/IT admin check directory and guest settings
- The account may have been removed or blocked in the school’s Microsoft 365/Azure AD tenant.
- The admin should confirm the user is still in the organization’s directory and in the correct class group/team.
- If the account is being treated as external, the admin may need to re‑invite it as a guest and ensure guest/external access is allowed for that team.
- Have the teacher re‑add to the class team
- Once the account is correct and allowed by the organization, the teacher (team owner) should add the user back to the class team.
- If the teacher cannot add the user, they must escalate to the school’s IT admin to fix the organization’s access settings.
Until the admin/teacher corrects the account and membership, the channel cannot be joined from the student side alone.
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