Payment could not be completed
Checkout UI shows premium.paymentIncomplete when the payment flow ends without a successful confirmation (generic client fallback).
Why this happens
Provider declined/canceled, network failure mid-checkout, confirm step failed, or an unexpected client error without a more specific message. Broader than gateway-not-configured errors.
Diagnose and fix
1. Retry once; try another method if offered.
2. Check Payment history and invoices — payment may have succeeded despite the UI message.
3. Admin: review provider logs and Payment settings (keys, mode, webhooks).
4. If a more specific error appeared earlier (coupon, balance, gateway), fix that root cause first.