Factorio seems to be saying that this function does not exist.
I changed production.lua as shown below as a temporary fix. (Forced value to 0.)
After this the game will start and the settings I changed seem to work ok in the game.

Also, is the 'fish' option a multiplier? Should it read 'fish multiplier'?

-- code in production.lua

if stack_data.size ~= 0 then
--stack_data.priority = PriorityFromStackSize(stack_data.size)
stack_data.priority = 0
for _, item in pairs(core_table["module"]) do
stack_data.name = item.name
AddSingleItem(stack_data)
end
end

Thanks.

Argh, didn't cleaned up everything I removed. Fixing asap

Fixed. Thank you for reporting

Edit: Also, I thought fish:fish (fish) was funny. I added a description in the tooltip that there is a "restriction" on what fish changes. Would be easy to add a second set for fish that are not capsules (I know some mods add more fish as items)