What happens when an application tries to use a checked-out rule while it's being tested by another developer?

When an application attempts to use a checked-out rule being tested by another developer, the system ignores the checked-out version and instead uses the latest active version of the rule. This behavior ensures that the development process remains stable and functional, preventing conflicts that could arise from using a version that may not be finalized or could have ongoing changes.

In this scenario, the application does not fail to execute or revert to an earlier version, as it can still operate based on the last verified and active iteration of the rule. This functionality allows developers to work on modifications without impacting the overall application until the changes are approved and checked back in, thus maintaining a smooth workflow within the team's development efforts.