Bit annoyed. Set off to do an easy one. It still works, but I used the wrong clue in a section. Technically it means there are two solutions, but one of them is one you rarely hear so the game is playable.

Is that fork and knife being interchangeable? Or is there another I missed?

Yep that's it BB. Fork and Knife. I realised after getting the puzzle ready and meant to swap fork for something else as I put it on the site. Then completely forgot. To be honest I'd never heard anyone describe the fork like that, but apparently it's a thing.