I'm trying to copy a collection of objects from one .blend file to another. I tried append, and then I tried copy and paste with 2 instances of Blender windows open. In both cases, the objects become invisible after they are appended or pasted
Original objects:
Pasted objects:
dimensions of pasted objects:
If I press N, I can see that the pasted or appended objects have a dimension of 0,0,0.
What did I do wrong?