While attempting to couple FEFLOW with MIKE-1D, I encountered a recurring error message: “No coupling reaches selected for MIKE-1D; coupling will not perform any exchange!” Here are the relevant details: 1. I possess a functional FEFLOW model that utilizes a fluid transfer boundary condition (BC). 2. Simultaneously, I have a MIKE11 file that runs smoothly. 3. Both models are aligned in terms of simulation time and spatial extent. 4. Additionally, I’ve carefully selected transfer nodes for mapping and ensured adequate grid spacing for MIKE11. Despite these preparations, the coupling process remains unsuccessful. If you have any insights or suggestions, I’d appreciate your guidance!