Running bobs/angels and i get this error for bob's green house on both recipes

The mod Max Rate Calculator caused a non-recoverable error.
Please report this error to the mod author.

Error while running event MaxRateCalculator::on_player_selected_area (ID 49)
MaxRateCalculator/control.lua:731: attempt to concatenate field 'amount' (a nil value)
stack traceback:
MaxRateCalculator/control.lua:731: in function 'calc_assembler'
MaxRateCalculator/control.lua:873: in function <MaxRateCalculator/control.lua:836>

Thanks for reporting this. I’m traveling, so it’ll be a couple of days before I can fix it. What were the circumstances?

I think it might have anything to do with bob's green house recipes, the seedling recipe made in assemble machines also causes the same error.
As far as i can tell there is only 3 recipes for bobs greenhouse and they all cause this to happen.

Those recipes use "amount_min" and "amount_max" for products.

Yes, the way uranium used to. I’ll be updating soon.