Worlds export error in realms

Very good morning to all.
I wanted to report an error in the Realms and this is that I bought the realm again but when I export a world of mine I get an error.
I already tried to solve it but it seems that I cannot and that is why I use this email in the hope that it works.
I can't import any world. Not even the new ones and I wanted to play Realms with my friends.