What I expected to happen was...:
I thought I would clone the command block and the command block would still have the same command and still work.

What actually happened was...:
I cloned the command block and if I give it a redstone signal or click done in the GUI it 1) just vanishes or 2) moves one block in any direction.

Steps to Reproduce:
1. Make a clone command in a command block like "/clone ~ ~2 ~ ~ ~2 ~ ~ ~-2 ~ ~ ~-2 ~" (Make sure your coordinates clone a command block)
2. Where ever the coordinates are, place down a command block with any command like /time set day,/summon ~ ~1 ~ Creeper,ect.
3. Clone the command block you just placed then click on the new (cloned) command block and click done.