In the updater is a windows font update.

[Wurm]

Originally Posted by Darqwood

If you are logged in when you check for updates, or if you crashed when logging out, the updater will report needing one of the special ProfitUI fonts. Log out of the game and check for updates and it should be all green.

It still shows it as missing, doesn't affect my UI at all as far as I can tell so I'm not worried about it