"Houve um problema ao entrar no mundo"

 

 
My cell phone hung up because it was discharged, and as soon as I plugged it in and loaded everything up correctly, I went to Minecraft to play there, I entered my main world, which had all my buildings and so on. I was playing in this multiplayer world with my sister, only after I hung up and maybe I went into the world and the following message appeared ... "There was a problem entering the world", this message still appears and I'm desperate why I don't want to lose this world. Can you help me?