For example, the command /testfor @e[type=item] work well, but the command /testfot @e[type=item] {Item:{id:stone}} don't work, even if there is a stone item on the ground
That's quite bad for commands blocks (i am nearly sure that the probleme doesn't come from me because it works in 1.11.2 and before)
MC-118469
Command bug
Resolved
Invalid
0
You need the namespace, and as such, quotes: id:"minecraft:stone", the namespace has always been required for testing.