When an exception is raised, the application is aborted, the action flow is interrupted, and continues on the Error Handler that first handles that exception, according to the exception handling mechanism.
In the example below, the CreatePurchaseOrder action raises an exception if some unexpected condition occurs. In these situations, the action flow is interrupted and continues on the exception handler.
What You Should Know
Service Studio does not let exception handler flows, and action flow intersect. This is made to ensure your application can successfully return to the end-user an error message. If both flows intersect, you will get an Invalid Error Handle Error.
Also, if you have error handlers on the screen flow, you should not connect them to screens with mandatory parameters. This is made to ensure that screens with mandatory parameters always receive arguments. In this situation, you will get an Invalid Error Handler Flow Error.
Handle Exceptions | Verify Error Messages