Has anyone encountered this behaviour before ? I have a script task

Per the documentation forum.appian.com/.../Exception_Flows.html:

- On an unattended activity, the activity and the exception triggers are started at the same time. It is not possible to determine which one completes first. This applies to Rule Events (as well as any Timer Events that have met their schedule conditions prior to node activation).

Depending on what error alert you were getting when the node was showing up the red line this documented constraint could explain the behavior.

Putting the expression in the output tab might work as you have seen because the expressions there get evaluated after the inputs but I'd still think this is prone to race conditions.

The documentation suggests the following:

- Configuring the Exception Flow on the subsequent node in your process ensures that an exception rule is evaluated in proper sequence for an unattended node.
- Configure a roll back of any actions taken by the previous activity, if you evaluate exception rules within a subsequent node.

Thanks for this Eduardo - I did catch that piece of info in the docs after I'd posted this - being a newbie Appian developer wasnt quite sure if Activity meant Input or not ... I'll put my thinking cap on