Weirdness in "select World" screen

When in the "Select World" screen, worlds usually have their name, their filename, when they were last accessed, and some modifiers like "Creative Mode", "Cheats", and "Version".

I am seeing "Version: TextComponent{text='17w49b', siblings=[]" and then continuing on past my ability to view on my old world, and my new world says the same except '18w01a'