Uploading world to Realms Java fails at Verifying World with Error code 500

I have a world I originally created on a realms server. I had been working on it in single player for some time, and wanted to upload it again to play with some friends. Selecting it to upload isn't an issue, and it uploads just fine. However, it runs into an issue when it's done uploading and starts to verify the upload. It hangs on that step for awhile before stating "upload failed" with an error code 500.

I've already tried resetting things on my end and tried reading through information online and the FAQ with absolutely no avail.