Made a quick bot to farm "Only The Strong Survive" (2219) in evilwarnul, but it always seems to be crashing upon pickup of Legion Blade.
I'm using the latest Cetera, and the bot only has two functions in it, joining the room + cell, and attacking random monsters.
I have a delay on the bot set to 2000 ms, because I assumed it was picking up items too fast, but that didn't seem to be the case.
The item is in the drop configuration to be picked up, and is spelled correctly and everything. I feel like it has something to do with Cetera declining it and accepting it at the same time for some reason.
As I stated, the bot only has the two functions listed, so there's no Get Drop function being used, just the whitelist.
I don't have any experience in Cetera, but I believe it's caused by declining and accepting drops.
Try in Carbon and see if it throws the same error.
BTW if you need a bot for it, Carbon has a built in bot for this quest. I believe it's called Diamond of Nulgath (evilwar).