Factorio Forums

Docs specify that CraftingMachinePrototype.working_visualisations is "array[WorkingVisualisation]".
Apparently it should be "WorkingVisualisation or array[WorkingVisualisation]" instead.
(noticed because Bio Industries uses the non array variant which broke my prototype deserializer )

No, it only allows an array of WorkingVisualisation. But all properties of WorkingVisualisation are optional, so when only a single WorkingVisualisation is provided it's not erroring in any way, it's just loading nothing.

You can see that happening if you turn on the unused prototype data option (via config or command line), because the properties of the single WorkingVisualisation will be logged as unused.