Affects Version/s: Minecraft 17w47a, Minecraft 17w47b, Minecraft 17w50a
Fix Version/s: Minecraft 18w02a
As of 17w47a the wall banners got split up per base color, and every block in the game has its own translation key.
But, wall banners only have 1 translation key: block.minecraft.wall_banner unlike all other blocks and is not actually used.
There should be block.minecraft.COLOR_wall_banner for each color instead, like the game tries to get.
This can be seen in CanPlaceOn and CanDestroy tags.
This can be fixed by adding the following to the lang file: