Error events are triggered by service and script task failure, for example if a script task has been configured to copy the value of one field to another and the field name is changed in the form but not in the script configuration then the script task will fail. If that script task has a connected error event, this will trigger the error event and redirect the process along the new path originating from the error event.
In the BPMN standard there are two kinds of error events, either an intermediate catching error event or an end throwing event. Error events can also be used as boundary events.
How to use Error Events
Intermediate catching interrupting boundary error events
Are used to cancel script and service tasks which fail their execution. The intermediate (yellow) event catches an error generated by the script or service task which interrupts the task and triggers the boundary event.
NOTE: Barium live currently only supports intermediate catching interrupting boundary error events which can be attached to script and service tasks.
Configure an Error Event
Error events are not configurable in themselves but when attached as a boundary event of a script or service task which fails they will trigger and interrupt the active workflow of the failed task and instead continue the flow to an associated outbound sequence flow.