I've recently tried to fix one of my custom modpacks (magic-based), and have gotten it to get to the main menu. However upon attempting to create a world the game will crash with this error:
The game crashed whilst ticking memory connection
Error: java.lang.IllegalArgumentException: Duplicate id value for 27!
Also here is the console (Fatals, Errors, & Warnings Only)
Where can I find these id's and how can I fix it?
-Note I can provide a mod-list if needed