I have the Same problem. But it isnt just on 11.3. I currently have CFW, but before i had that still happend to me. My 3ds reboots fine after the error.
Did you read everything? Becouse the thread says: "This might not work on 11.2, so don't be surprised if HANS gives you an error!". But you can use OnionFS just install ahl9.
Yay finished the game (kinda you need to replay the whole game again if you beat it wtf). This tool helped very much even tho the names are english and my game is german.