A common bug when duplicating items is the "invisible item" issue, where edited items don't appear in-game. Newer editors now forcibly reset item slots from 0-910 to ensure all modified gear displays correctly in your stash.
If you encounter persistent "corrupt data" messages, it may be due to bad sectors on your SD card. You can fix this by archiving the game, removing the SD card, and downloading the game directly to the Switch's internal memory. Troubleshooting Corrupted Save Data diablo 3 nintendo switch save editor fix
Some users have successfully fixed corruption by launching the game to create a new save, then using a text editor like Notepad++ to selectively copy values (such as inventory data) from the old corrupted file to the new one, excluding system-specific reference lines. Seasonal vs. Non-Seasonal Limitations A common bug when duplicating items is the