I downloaded my Realm world in order to take it with me on my Switch, then I closed the realm. When I got back home, I tried to replace the world on my realm with the downloaded one, but in the middle of initializing the upload, the game returned a "an error has occurred" I tried re-opening the realm, but it still returned the same message.

How to reproduce:

1: Download realm world

2: Play on world

3: Replace world on realm