Apologies in advance, if this is not a method error, but a script error. I was trying to add a Coil:WaterHeating:Desuperheater which collects heat from a Coil:Cooling:DX:SingleSpeed and rejects it to a WaterHeater:Mixed object, per the EnergyPlus IO reference for this object. This object is present in the Openstudio 1.14 sdk documentation.

I used user inputs to choose the WaterHeater and the CoolingCoil required, and used the addToHeatRejectionTarget method to add the OS:WaterHeater:Mixed as the rejection target, and the setHeatingSource method to add the required Coil:Cooling:DX:SingleSpeed as the heating source. The script executes properly (Apply Measures Now), as shown. The Water Inlet/Outlet Nodes have been attached from the OS:WaterHeater:mixed selected, and the Heating Source Name has also been assigned. However, when I run the simulation, I get a severe error saying that the Heating Source Name has not been translated into the idf (image).

This makes me believe that it's an OS internal issue. Is that right? Or is there another way/pseudo code through which this can be fixed? Or do I have to insert this object directly in the idf using an Eplus measure?