The recipe for Wither essence is missing making the chaos dragon woot farm unusable.

Recipe from Remix. scripts/balance/atmcreativeitems.zs

//====== Wither Essence ======
//
var witheringSoul = mysticalagradditions:stuff:1;
var dropOfEvil = extrautils2:ingredients:10;
var witherDustBlock = ore:blockWither;

recipes.addShaped("atmWitherEssence", <atmtweaks:item_material:10>, [
    [witheringSoul,	  witheringSoul,   witheringSoul],
    [witherDustBlock, witherDustBlock, witherDustBlock],
    [dropOfEvil,      witherDustBlock, dropOfEvil]
]);