Hello guys, I’m doing a 1d-2d model with a storage area upstream representing a reservoir. With this model, I get instability errors when running the unsteady state solver. At the top of my head it could be because of large volume of water from dam release or it become unstable when water crosses the 1d-2d lateral structure (not a true weir but boundary is needed between 1d and 2d areas). Anyways I’ve tried removing the reservoir and inline structure and just inputting a flow in the upstream end of the reach. However, it still becomes unstable. Any tips?