I am uploading one of my single-player worlds to my realms world. I have successfully uploaded previous worlds to my realm with no issues but for some reason, my worlds aren't uploading to realms. When uploading the world, it goes all the way to 100.0 % and says  "verifying your world " for about 8 minutes to 10 minutes time. After an amount of time, it gives me the red text saying "Upload failed! (500)".