Captcha enabled but provider not configured
Login or register tried to submit while captcha is required for that form, but the provider’s public key is incomplete. Product text: captcha is enabled but the provider is not configured.
Why this happens
login_captcha_enabled / register_captcha_enabled is on, and captcha_mode keys are missing. Client blocks submit. A page banner may show the shorter Captcha is not configured sibling.
Diagnose and fix
1. Admin → Settings → Captcha provider — pick mode and fill public/secret keys.
2. Enable only the surfaces you need (Captcha on login / registration).
3. Hard-refresh login/register and confirm the widget appears.
4. Related download/comment misconfig uses similar wording in other articles.