When computing a model, the following error message is generated: "There is no conduit connected to the outfall, or the conduit is inactive." It is possible to view hydrograph data, but there are no results at the outfall.
In the OpenFlows storm-sewer products, an outfall needs to be attached to a link, such as a conduit. If you are trying to model a pre-development case where the runoff from a catchment goes directly to an outfall, you would need to include a node (such as a transition or a manhole) and a link (such as a conduit) to see the results. The conduit can be sufficiently sized to minimize the headloss.
If you are performing a pond design with a pre- and post-development case, you may also want to consider using PondPack. In PondPack, you can directly connect a catchment to an outfall without an error message.