Error 500 when trying to upload a world

I try to upload a world to realms and it gets to 100% and then when it gets to verifying it immediately says "Upload failed! (500)". This all happened after it said my world i was replaced was "outdated". 

 

How to i fix this? I need to know

Also this is Java 1.13.2 but I don't know what "version" that is.