Blender Crashing..

Hello all,
I am importing some objs from DAZ to Blender…I have 3 buildings in the scene but if I add a 4th… Blender crashes when i render. Can anyone tell me why this is happening and what the remedy is if there is one. Please. Thank you. I feel blender should be able to create more complex scenes than than just 3 objs.

#1 How many polys?

#2 What is your OS?