Problem

* A filter is red, indicating that it is missing an attribute and you are not sure how this attribute should be created.

Resolution

-- In general, when you see a filter marked as red in the Circuit Editor, this means that a required message attribute has not been populated by a previous filter or HTTP Interface. To find out how to populate that message attribute, a good place to start is to right-click on the filter in the Circuit Editor and select "Create Predecessor." The menu then displays all the filters that generate that missing attribute.