It is sometimes caused because of bad geometry in the model. These are the errors you find in the Report or it keeps on popping up everytime you move around in the model. One fix is to try finding the bad geometry and fixing it.
Do you have any geometry that you have imported from Rhino or Sketchup?
Sometime it is due to complex geometries ... consider that even 50 doors could be a "complex" geometry.
Try to exclude doors and windows from the 3D view to be exported and check if the doors/windows are the cause of the issue