This sign-in provider is not configured
Social login callback (or start) found no usable credentials for the provider (oauth_provider_not_configured).
Why this happens
Provider toggled on in the UI but client ID/secret missing, or provider disabled in Social login settings. Distinct from Sign-in was cancelled or denied and from failed token exchange.
Diagnose and fix
1. Admin: Settings → Social login — enable the provider; save client ID/secret.
2. Confirm OAuth redirect URI matches the live site.
3. Member: use another provider or email/password until configured.
4. See Google login / provider-specific articles for field names.