team user cannot login

Hello

I see that it is a personal account there but looks like that personal account could be also a guest user in an organization tenant.

You need to tell me though, is it having issue when logging as the personal account itself, or is it having issue logging in as the guest user in the tenant?

And what's the specific error message if any, or the exact behavior if you can describe it?

Is this happening on Win11, MacOS or phone?

Does it work if you go to web browser inprivate mode https://teams.microsoft.com/v2?

For intermittent Microsoft Teams sign-in issues, use these checks and tools:

1. Confirm the correct account type
   • The screenshot shows a personal Microsoft account (for example, Hotmail). If the user should use a work or school account, make sure they select Work or school account (公司或學校帳戶) instead of the personal Microsoft account.
   • If they see missing Teams, meetings, or assignments, they may be signed in with the wrong (personal) account. Ensure they sign in with the organization-issued work or school account.
2. Use the Teams status code
   • When the user cannot sign in to the Teams desktop app, look at the status code shown at the bottom-left of the Teams sign-in window.
   • Record that status code and check it against the sign-in troubleshooting table, or send it to the organization’s IT admin or sysadmin to diagnose the issue.
3. Check organization / tenant access
   • If the user still cannot sign in, there may be a problem with the organization’s domain or Microsoft 365 tenant configuration (for example, licensing or domain issues).
   • In that case, only the IT admin or sysadmin can fix it. Provide them with the user’s UPN and the Teams sign-in status code so they can investigate in Microsoft 365 and Entra ID.
4. If Teams keeps asking to sign in again
   • Teams may force re‑sign‑in if:
     • A VPN or specific network is required and not connected.
     • A sign‑in risk is detected and extra verification is required.
     • A password breach occurred and the password must be changed.
     • The device no longer meets organization requirements.
   • Have the user complete any required verification or password change and retry.

If the problem persists and the status code does not match any documented case, escalate to the organization’s IT admin with the exact error and status code for deeper investigation.

References:

• Why am I having trouble signing in to Microsoft Teams?
• Signed in to the wrong account in Microsoft Teams Free
• Restore your access to Microsoft Teams