Many of you have noticed Minecraft no longer launching vanilla version 1.13 since it has released. This is because Mojang has changed their URL pattern they have historically kept for many, many releases.
https://s3.amazonaws.com/Minecraft.Download/versions/{0}/minecraft_server.{0}.jar
This URL used to work, for pretty much every modern version since their 1.0 release. The pattern still downloads something–in this case it’s XML for an error message. It says ‘downloaded’ because there is, in fact, a file called minecraft_server.1.13.jar, it’s just that it contains no usable game code. Here’s what the URL might potentially could have changed to:
https://launcher.mojang.com/mc/game/1.13/server/d0caafb8438ebd206f99930cfaecfa6c9a13dca0/server.jar
That is, not a dependable, versioned URL, but instead a URL that could have a long SHA5 or other checksum in the URL itself.
If you want to play Minecraft 1.13, you still can, you just have to download the file manually and place it in your server’s live directory (/var/games/minecraft/servers/[myserver]).
Alternatively, you can instead replace the dummy file that exists in /var/games/minecraft/profiles/1.13 so you can continue to use the profile as normal. (this would be preferred, really). Be sure to re-copy over the new jarfile by clicking “copy profile to live server files” after doing this overwrite, too.
I’ll try to look into this further to find out a way to programmatically download this server jar without really sloppy code, but at some point it’s just them making things needlessly complicated just so we can race after them.