I am the pack dev for meatballcraft, which uses the latest version of MMCE.

After updating, I merged the old modular magic multiblocks with the built in hatches, but multiblocks with essentia output hatches are unable to produce output, and show a 'Can't output essentia' error in the controller gui.

Yup, here is the file for the multi. You will need thaumcraft and thaumic additions to have all blocks used in the structure.

mechanized_essentia_smeltery.json

And here is a piece of the script to go with it.

import mods.modularmachinery.RecipeBuilder;


val esse1 = RecipeBuilder.newBuilder("essdisso1","mechanized_essentia_smeltery",5);
esse1.addAspectOutput("aer",1);
esse1.addItemInput(<thaumcraft:crystal_essence>.withTag({Aspects: [{amount: 1, key: "aer"}]}));
esse1.build();

val esse2 = RecipeBuilder.newBuilder("essdisso2","mechanized_essentia_smeltery",5);
esse2.addAspectOutput("terra",1);
esse2.addItemInput(<thaumcraft:crystal_essence>.withTag({Aspects: [{amount: 1, key: "terra"}]}));
esse2.build();

Now works will in R51 :)

Is there an example used for testing? I need a way to reproduce it.