«This sign-in step was already used.» (continuation_consumed)

Symptom

In the second sign-in step (one-time code or second factor), «This sign-in step was already used. Enter your password again.» or «The additional confirmation is no longer available. Enter the password again.» appears. The API answers 409 continuation_consumed.

Cause

The second step works only once. It happens when:

• you pressed «Confirm code» twice or repeated the request;
• you opened the sign-in page in two tabs and finished in one of them;
• the browser went back and resent the step.

Fix

1. Choose «Cancel and start over» (or reload the page).
2. Type your password again.
3. Use a new code from the authenticator app (the previous one may already be spent).

How do I avoid it?

Sign in in a single tab, and do not use the browser's back button or reload during the second step. Each continuation can be used once.

When to escalate

If it always happens, even in a single tab without repeating, contact support with the time and the browser used.