Still happens on non-cracked versions. The outline is just at (0, 0, 0), just like MC-106539
http://imgur.com/a/Xarmm
Ugh. Nearly every time I post something, I search and search, never finding anything relating to what I'm about to post, but then I find a duplicate AFTER I post.
Don't hate this for being a duplicate. It was fixed then came back.
I searched and searched, but didn't find any duplicates. Then I posted it and it gave me some. Oops. 😞
This isn't a bug. This is perfectly normal. When the button is pressed, it updates the block under it. That update is then picked up by the observer and it puts an output of one tick. The output then powers the piston, causing it to extend. Here's the thing though: When a sticky piston receives a one-tick pulse, they only push out the block. They don't bring it back in. This is what you are seeing.
What you have there is a very simple T flip flop. You can use the block as an output, and every time you hit the button, it switches from on to off (Like a lever, but with a button instead)
I hope all that makes sense
Cheers
--PumpkinOverlord