If you’re on a Turkish version of Windows, change your region in Windows to English then re-start the client. (There’s a wacky bug related to the fact that Turkish uses a different Unicode character for the letter ‘I’)

If that’s not the case, and relaunching isn’t fixing things, uninstall and reinstall should work (don’t worry, all of your collection data is stored on the server; you won’t lose anything by uninstalling.)