Abnormal redstone, piston, observer behavior (the redstone dust constantly powered)

Needs to be more descriptive. What here is abnormal? Slime blocks being solid isnt a bug, if that's it.

Observers give off a 2-tick pulse at the moment, and Repeaters and other components can get stuck when powered by a 2-tick pulse. If you are having this issue in Pre-2, I'd suggest making a comment on the previous report MC-151057

Duplicate of MC-151418