Sorry I don't speak German, it seems editing the items just crash the game now. Like you can edit everything else but as soon as you edit an item, the game doesn't launch anymore. It didn't happen before the update a few days ago, and even disabling the dlcs doesn't change a thing.

The last dlc did add like a hundred of new items (artifacts for the museum), and it looks like the modding tools couldn't handle it ... I guess all we can do is wait for the devs to notice and fix this.