The blank screen is a common problem due to mis-aiming.
You might request a preset view or place a camera in the scene aimed at the building, select that camera and see if it images.
As for the memory issue - the size of the file is irrelevant. Users can't seem to understand that a file can become huge as a 3D model and not so big as an Archicad file. But nevermind - this is probably a corrupted element. Troubleshoot by imaging only half of the layers at a time until you locate the layer of the faulty element.
Dwight Atkinson