Command blocks not saving

Put the summary of the bug you're having here

What I expected to happen was...: 
When I pressed done with my command, and open the command block again, there should be the command that I was working on

What actually happened was...:
I was using command blocks and writing a really long command, and when I pressed done button on the left corner, and opened the command block again, and all the commands I typed were gone.

Steps to Reproduce:
1. Type in any command in any kind of command block even the chain, and the repeating command block
2. Press the 'Done' button
3. Open the command block again and all your typed commands will be gone! Woohoo! Your work has been reset.