Error replacing my world in the realm

Hi! I'm a new player of Minecraft on mobile. I bought a realm for two players, I wanted to replace it with my world and I get an error. All good at the time of exporting, but then I get an "error"

 

Is not an internet problem because I tried with other Wi-Fi and the problem continues. My world weighs 30 Mb. 

Please, help, I wanna play.