I can't sign into my Security Center due to authenticator lock loop

The account is effectively locked in an MFA loop where the only available methods are the Microsoft Authenticator app and its verification codes, and the app itself is not completing authentication.

Based on the documented behavior, there are two separate issues to address:

1. Fix the "Authentication did not complete" problem in Microsoft Authenticator so at least one existing method works again.
2. If that cannot be fixed, escalate to Microsoft support to have MFA reset for the account (especially if this is the only admin account).

Follow these steps in order:

1. On the device with Microsoft Authenticator, fix the app-side issues that can cause the "Authentication did not complete" loop:
   • Ensure the Microsoft Authenticator app is unlocked before trying to sign in. If the app is protected by PIN/biometrics, unlock it first, then retry the sign-in.
   • Check that notifications are enabled and not silent for Microsoft Authenticator on the device. If notifications are blocked or silent, the approval prompt may never appear. Also check SMS messages in case codes are being delivered silently.
   • Confirm the app is updated to the latest version from the app store. An outdated app can cause the authentication flow to fail.
   • Verify the device has a stable internet connection. If necessary, switch between Wi‑Fi and mobile data and retry.
   • Ensure the device date and time are set correctly (prefer automatic network time). Incorrect time can cause code and token validation to fail.
   • After checking all of the above, attempt the sign-in again using “Approve a request on my Microsoft Authenticator app” and then “Use a verification code” from the app if push still fails.
2. If repeated attempts have triggered a protection block (for example, “Try another verification method” or similar messages):
   • Stop making repeated attempts for a while; high volumes of sign-in or verification attempts can cause temporary blocks.
   • If another verification method is configured on the account (alternate email, SMS, etc.), try switching to that method when prompted. If the block is tied to one method, another method may still work.
   • If possible, try signing in from a different network (for example, switch from home Wi‑Fi to mobile data or another Wi‑Fi network) and then retry.
   • If a block persists, wait up to 24 hours before trying again; repeated attempts can reset the time lock.
3. If none of the above restores access and the only sign-in methods are Authenticator-based (no working SMS/email/security key), the account’s MFA configuration must be reset by Microsoft support:
   • For a personal Microsoft account, use the sign-in helper referenced in the verification-code troubleshooting article to start a guided recovery and surface available support options.
   • For a work or school account where this is the only administrator account and all admin sign-ins are blocked by broken Authenticator, contact Microsoft support by phone and request escalation to the Microsoft Data Protection team to reset MFA methods on at least one admin account. Be prepared to verify identity and tenant ownership.

Until at least one verification method is restored or reset by support, access to sensitive areas such as the Security Center and security settings will remain blocked by design.

References:

• Troubleshoot problems with Microsoft Authenticator
• Troubleshoot Microsoft verification code issues
• Authentication did not complete
• Common problems with two-step verification for a work or school account
• How Do I Regain Access to My Account After Losing Access to Microsoft Authenticator? (Urgent Request). - Microsoft Q&A
• I have a Micrsoft business account and I am the admin and the only user registered under this account. I can't log in because i have replaced my phone and the authenticator doesn't work. - Microsoft Q&A