Hello. We ran CDocker function on a specific receptor and a ligand. We had two different receptors. With one receptor, docking was completed successfully. However, when we tried the same procedure with the second receptor, docking failed. There was this error message within the results: "No refined poses found for ligand". We used the same ligand file for both docking inputs. Why would the second docking reject the ligand? 

Please help.
Thank you.