Why have my appended objects lost their rigid body settings? I am working on a scene in which a wrecking ball on a chain crashes through numerous glass cubes. 

I created the chain and ball in a different blender file to work more quickly, since the numerous cubes made modelling slow. I created materials for the ball and chain and then made rigid bodies correctly so the chain and ball would swing realistically. 

Now that I have appended the chain and ball (About 10 individual objects) from my first blender file into my current file with the glass cubes, the ball and chain no longer move when I press play even though they still appear to have their correct rigid body settings. 

It seems that importing multiple objects, each with their own rigid body settings is problematic. Is there any way to get my wrecking ball and chain into my file with the glass cubes without having to remake them within the glass cube file?

Thank you for your time?
This is because there is no Rigid body world in your second file.
To fix this:

Press Add rigid body world in Properties &gt; Scene &gt; Rigid body world:


With your appended rigid body objects selected, press CtrlG to make a group. They should now have a green outline:


Select the group in Properties &gt; Scene &gt; Rigid Body world &gt; Group: