these posts are really old but I have just started learning City engine and I have faced same problem, hope someone would check up here.
I am trying to create the Redlands project from the tutorials. I managed to bring the terrain and the aerial projection on it but when dragging the .OSM file I get the error "The data is located too far from
the current scene's contents. Either edit the (geo-)location of the data, choose an adequate projection, or import it into a new empty CityEngine scene."
I have tried importing them in different scenes and they are really in two different locations. I also suspecting the scale of OSM being very different, but I'm not sure.
I have tried downscaling the terrain as suggested but it is not working.
I would appreciate any guidance