Symptoms

Although CAPTCHA is enabled in the JIRA Administration Panel (CAPTCHA on signup ON), a CAPTCHA does not appear regardless of invalid login attempts. Nothing appears in logs.

Cause

This may be caused by customizations of Seraph authenticators ($JIRA_INSTALL/atlassian-jira/WEB-INF/classes/seraph-config.xml). If you want to get CAPTCHA working, please refer the external authenticator set on this file.

Resolution

Backup and replace your $JIRA_INSTALL/atlassian-jira/WEB-INF/classes/seraph-config.xml with the original version you're using. If anything else has been changed when implementing the external authenticator, roll that back also.