When attempting to upload a world to realms, it always reaches 100% then stops at verifying your world. After being stuck on that screen for a few minutes, a message will pop up saying either "Upload Failed -1" or "Upload Failed 500". The world size is less than 500mb. I have tried on several computers and networks, nothing seems to work. I am able to upload other worlds (notably smaller) to the Realm but not the world I am meant to upload. 

When I attempt to join the realm after the upload fails, I get an "invalid session, try restarting the game" message. I have also attached part of the log.