After applying the 8.0.2 update, visitors may notice a captcha error being erroneously displayed for a split second when performing a domain lookup in certain circumstances.

A hotfix has been created for 8.0.2 only to improve the display of this option:

https://whmcs.community/files/file/144-core-15495-erroneous-captcha-error-on-domain-checker/

1. Navigate to Configuration > System Settings > General Settings > Security tab
2. UNtick the Domain Checker option
3. Click Save Changes