I am trying to make a quest where the player kills mobs in one stage, and in the second stage returns some of the remains. Blaze rods, nuggets, and spider eyes. I get the error the item list and npc list are not equal in size. Thanks in advance!

Not sure how i'd fix that, but I'd go around it by making multiple stages that asks for each of the items.

So Stage 2 would ask for Blaze Rods
Stage 3 would ask for nuggets
and Stage 4 would ask for the spider eyes.

However, it may not be ideal in your situation but a temporary fix until the author or someone with more knowledge helps you out.

I found out a bit later just by reading what it was saying. I just had to repeat the NPC ID the same amount of times as the number of items I had. So if the NPC ID was 11 and I had 3 items, I would do ' 11 11 11 ', for choosing the npc.

If I understand correctly, this issue has been resolved. Otherwise, please create a new ticket. Thanks!