Hi there i am using latest ItemBlacklist. ItemBlacklist-1.4.3.

I have blocked some Items in Singleplayer via Pack-Command. There is written an output in Chat. And Item is blocked with Pack-Command. But i havent found any ItemBlacklist.json. If i ban Items on a Server, i get the Information. If i type List, i get the Items that i banned. But a normal Player can still interact with that item. And even me. I have tried with Op-Account, then i have tested it with my second Account (not Op just normal Player) and it was the same. I have taken my Pickaxe and mined that Resource, and i am able to use it.

It certainly does work on servers.
Either you are using something that breaks permissions or your not using a Forge server.

Item Blacklist saves the banned items in the world folder as mentioned on the CurseForge project page.

As there has been no follow up on this It's getting closed.