Jan L.

Could you describe the steps needed to reproduce this?

Are you sure, that it works as intended?
I did some research and in 16w20a it works like I intend. If I save using redstone in 16w20a, a new file generates AND buttons are working fine.
In 1.10.2, buttons still seem to work, however, no file generates.

I kept the original post and removed the 2nd edit, because it seem to work as intended. 3rd Edit is explaining the actual problem.

Ok, well, this is a really annoying and useless feature, but this, still does NOT work as intended:

5. Change the pattern.
6. Save the pattern using a button.
7. Load the pattern using a button.
Well, you should see the old pattern.
It didn't even save to memory. It didn't save at all!