Today I update forge to 36.1.12 and got this

But my BOP is: BiomesOPlenty-1.16.5-13.1.0.441-universal
Game version:1.16.5
Aquaculture mod version: Aquaculture-1.16.5-2.1.16

That does seem very weird, as you're using a newer version than we require.
I'll take a look later.

What Minecraft Forge version are you using? I think this might be caused by changes in Forge version 36.1.10, so try using 36.1.9 :)

@GirafiStudios Thanks for reply. I'm using forge 36.1.12, and the game do work well in old versions. I thinks I shall downgrade forge first and waiting for an fix :)

@PhyX-Meow, could you try this Jenkins version, with latest version of Forge too? :)
https://jenkins.girafi.dk/job/Team%20Metallurgy%20Mods/job/Aquaculture/job/Aquaculture%202%201.16/80/

You fixed it it just as I commented on it. Girafi, why are you so good at this?

@GirafiStudios Wow, what a quick fix. I would try it tomorrow, now it's 00:04 in my timezone.

Great! I got up my bed and opened my pc, and everything works fine now.
Cheers.

Thanks for confirming that older versions do work :)