To replicate:
Go into F3 mode.
Point at Comparators, Repeaters, Mob Heads, Flower Pots, Cobble walls of either type, or Stone of any type.
The names here are incomplete, they all say tile.comparator.name or something like that.
Attachments
Comments 2
This duplicates MC-51037.
EDIT – Oh it doesn't.
Question: Are the block names in 14w11b supposed to be the way they are?
Block: minecraft:red_flower/3
The issue in 14w11a is now fixed, but it was replaced with this new 'b' naming convention. I'm not sure if that was intended or not.