Some errors when starting 15w43c

When i am starting minecraft, then immediately close it, i see in the game output some errors:

[15:28:06] [Client thread/WARN]: Missing sound for event: minecraft:enchant.thorns.hit

[15:28:06] [Client thread/WARN]: Missing sound for event: minecraft:entity.guardian.thorns

[15:28:06] [Client thread/WARN]: Missing sound for event: minecraft:entity.horse.eat

[15:28:06] [Client thread/WARN]: Missing sound for event: minecraft:entity.rabbit.attack

[15:28:32] [Client thread/WARN]: Unable to resolve BlockEntity for ItemInstance: minecraft:shield

[15:28:32] [Client thread/WARN]: Unable to resolve BlockEntity for ItemInstance: minecraft:shield

Completely ignored arguments: [--nativeLauncherVersion, 286]

Just open minecraft in 15w43c and close it after, don't know if it's in older versions