when you try to replace a specific block like redstone with sandstone it will work properly:
~/fill ~ ~ ~ ~ ~ ~ minecraft:redstone_torch 4 replace minecraft:sandstone 0~
the redstone torch ONLY replaces sandstone.
but if you try to do it with comparators like this:
~/fill ~ ~ ~ ~ ~ ~ minecraft:unpowered_comparator 4 replace minecraft:sandstone 0~
you will get an error saying it doesnt find brackets. so the correct way it doesnt give an error is like this:
~/fill ~ ~ ~ ~ ~ ~ minecraft:unpowered_comparator 4 replace {} minecraft:sandstone 0~
but then it ignores the sandstone and replaces any block
Linked issues
Comments


Dupe of MC-61864
From Searge: "Replacing blocks with tile entities is not supported, this is due to a limitation in the parsing of commands. It may be changed in the future, but not until after 1.8. This issue should be considered a feature request, not a bug."
Duplicate of MC-61864
Comparators are a block entity.