When computing a model in PondPack, the following user notification is generated: "The composite outlet structure is either not selected or deleted."
The likely cause of the issue is that the Pond Outlet link has been set to include a control structure, but no composite outlet structure has been selected, or the composite outlet strucutre that was previously selected is no longer available.
The Pond Outlet link element in PondPack is used to convey flow from the pond to a downstream channel, outfall, or pond. The Pond Outlet link element is connected to the Pond Outlet Entrance node and a downstream node, typically a junction or outfall. The Pond Outlet properties are fairly simple. A sample of the how the element properties look is shown in the screenshot below
If you set "Has Control Structure" to No, it will be assumed that the flow coming into the pond will be equal to the flow coming out. If the pond has a Composite Outlet Structure associated with it, you will need to set "Has Control Structure" to Yes. You can then select a composite outlet structure from the dropdown menu at the property field "Composite Outlet Structure." If you have not yet created one, you can select the "Edit" selection from the dropdown or go to Componenst > Composite Outlet Strucutures to create one.
The user notification "The composite outlet structure is either not selected or deleted" occurs when "Has Control Structure" is set to Yes, but a composite outlet structure is not selected. If you have already created one, simply click in the dropdown in the property fild "Composite Outlet Structure" and choose the composite outlet strucuture. If you have not yet created one, you can choose the "Edit" option from the dropdown or go to Components > Composite Outlet Structure to create one.