Un-existing Action Used
The Un-existing Action Used analyzer detects when your logic contains a step that calls another action, but that action no longer exists.
This typically happens when an action is deleted after another action was already configured to call it. The calling step now points to nothing.
How to fix it
Open the flagged function instance and either select a different action to call, or remove the step if it's no longer needed.
Severity
Major/Bug - the action will fail at runtime when it reaches this step.