Unfortunately, it appears that the issue is caused directly by the current version of DyWorld, erroneously replacing all instances of assembling machines from other mods' recipes, that it doesn't define afterwards. Specifically, it is replacing the assembling machine 1 from the tier 1 reverse factory, with an undefined dyworld-stone-assembling-electric.
I could attempt to overwrite his overwriting of my recipe, but I feel this is an issue which should be solved from his end, since it affects more than just my mods.