I'm trying to mine IC2 mod blocks, but I receive an error saying "Error at argument #1: Expected aa"
I thought you could mine mod blocks too just by specifying mod:block. In this case, I want to mine copper, so the block ID would be IC2:blockOreCopper, but I just get that message. Is there something else I could do to get this running?

Are you sure IC2 is the modid, as it should be actually ic2
Do bare in mind, especially in the case of modded blocks, that the id is case-sensitive.

Yes, you do.

Are you sure IC2 is the modid, as it should be actually ic2
Do bare in mind, especially in the case of modded blocks, that the id is case-sensitive.

How can I get the real blockID?, in F3 says the ID is "ic2:resource type:copper_ore", but in the wiki, it says It's IC2:blockOreCopper

I already tried with
IC2:blockOreCopper,
ic2:blockOreCopper,
ic2:blockorecopper,
ic2:copper_ore,
ic2:orecopper,
ic2:ore_copper,
ic2:resource:type:copper_ore,
ic2:resource type:copper_ore

This isn't a baritone issue really, it's with however your mod stores block names.