On September 30, 2021, LaunchDarkly introduced a bug in its frontend code. The issue was identified around 14:00 PDT, and a fix was implemented by 14:30 PDT on the same day. The incident was officially marked as resolved on October 6, 2021.

The bug caused an error page to be displayed when users attempted to use the rule attribute selector within the flag targeting web interface. This problem specifically affected environments where one or more private attributes had been declared within a LaunchDarkly SDK, preventing affected customers from utilizing this feature.

The root cause was a bug introduced in the frontend code on September 30. The company’s existing test suite did not cover the specific scenario involving private attributes for this component, which allowed the bug to bypass detection during the development cycle.

To resolve the incident, the team reverted the problematic change, which restored full functionality. As a preventative measure, LaunchDarkly is implementing both unit and integration tests to cover this and other frontend code when private attributes are in use.