Unity 3d .FBX from Google sketchup

I created a scene in Google sketchup of london. It has several different tabs/scenes in one sketchup document.

I exported it as a 3d .FBX, and i dragged it to the assets tab in Unity.

I generated colliders for it… But when i drag it into the game area, the restricted symbol (a circle with a line through it) comes up.

Why won’t it let me use it?

Make sure you are dragging prefabs and models into the Scene view, not the Game view. Alternatively you can also drag prefabs and objects into the Hierarchy; if done this way the model will be positioned at the Prefab’s default Transform values. Let me know if this still doesn’t work for you!