I'm currently trying to upload my world to a realm I recently purchased and its is coming up with "An error occured" every single time I try to upload it is there a fix?

While uploading a world to my realm I have been experiencing problems when uploading the world and have consequently not been able to use my new realm because of these issues is there a fix or a way to refund for the is broken feature? My Internet connection is fine FYI just a poor excuse