Hello!
I recently discovered exploit with basket.
Basket in inventory (as item) isn't locked and can be just dropped.
Open basket, throw away basket, take items to dupe and close the inventory.
Maybe it's not really OP, because you can't dupe diamonds, iron etc., but you can duplicate berries = infinite food or saplings on skyblock.

Bye

I have a Basket in a chest. When I try to take the Basket and move it the game freezes & Crashes.
The game crashed whilst rendering screen
Error: java.lang.AbstractMethodError: Method azmalent/terraincognita/common/integration/quark/BasketDropIn.canDropItemIn(Lnet/minecraft/entity/player/PlayerEntity;Lnet/minecraft/item/ItemStack;Lnet/minecraft/item/ItemStack;Lnet/minecraft/inventory/container/Slot;)Z is abstract
Exit Code: -1
debug.log

I have a Basket in a chest. When I try to take the Basket and move it the game freezes & Crashes.
The game crashed whilst rendering screen
Error: java.lang.AbstractMethodError: Method azmalent/terraincognita/common/integration/quark/BasketDropIn.canDropItemIn(Lnet/minecraft/entity/player/PlayerEntity;Lnet/minecraft/item/ItemStack;Lnet/minecraft/item/ItemStack;Lnet/minecraft/inventory/container/Slot;)Z is abstract
Exit Code: -1
debug.log

Please create a new issue as what you are describing has nothing to do with what QinomeD is talking about.

Fixed in the release version!