Prefab's lost!or is it there?

I have a prefab of a simple building..it was working fine.and i kind of re-arranged stuff in my scene, then when i when went back and played it, the prefab's lost. All the cubes layers are still under the CN prefab on the hierarchy, but it's not showing. It still has the xyz handle, but nothings there.Is it hidden or something?how can i fix this?HELP!! Tried changing the material on the inspector, but still didn't fixed it. What might be the problem?

Is the label for it sorta pink? Then it may be pretty lost, but there's a ReplaceSelection script in the script wiki that can help. Otherwise, try the Reconnect button in the Inspector.