Yeah, I have a glut of modded weapons, throughout the game I was a modded weapon owning madman
It seems the only option i have in new game is to delete the save or start with a new character. I was able to back up my save, maybe I'll send it in to them so they can see why this sort of thing happens
This is how you start a new game with existing save:
https://www.youtube.com/watch?v=2j3JWUc2HIE
Basically, choose new game, select character, choose chapter, then choose existing save to copy from.
I started doing every so often when my save got corrupted so I wouldn't lose everything. Also handy for when you "accidently" lose one of your best weapons when crafting ammo and it gets dropped on the floor and you didn't realize until too late.