Appended object doesn't let others render

Hi. I have a weird problem. I appended an object from another file and once I did that it doesn’t let the non-appended objects in the scene render. They’re just totally invisible. Why is this?

Maybe check the outliner? the camera button.

I recently experienced a weird problem like this when using Linked assets on Blender 2.6.3. They would not render at all but they occupied space within the render, leaving kind of square background where they should have been but the sky was there instead. Like they were masked out by some big bounding box.