Complete the captcha before submitting
Support/contact/ticket create returned support.captchaCompleteSubmit (also on tickets.form.captchaCompleteSubmit) when submit is blocked until captcha is done.
Why this happens
Captcha required on that form. Send/reply uses Complete the captcha before sending. Comments may use Complete the captcha before posting.
Diagnose and fix
1. Complete the captcha, then submit.
2. If the widget never appears, site keys may be missing (site-key-missing article).
3. See Captcha on contact / Captcha on tickets / Captcha on report abuse.
4. See Contact form (member) for contact-specific help.