couldnt find any conformation completely with the search space

Never had this error, and I suspect not many others did either. So that leaves us with taking it literally, which would indicate that a wrong search space was selected. That could mean too small of a search space, in the protein core where noting can bind, or maybe completely away from the protein. Your description is not enough to distinguish between these possibilities. I suggest you make sure that the software works by running one of the examples or tutorials, and then try to understand what was wrong with search space selection.