I've had this bug before when I first bought blockland.
It's a problem with your computer language on start-up. You have to go to your language settings and set it to English so no such thing happens.
Problem is, I can't even communicate with him at all, I don't even know his native language because his chat is broken.
Ctrl + ALT to switch language has no impact at all on in-game chat, too.
I don't know if a bug report belongs in Suggestions and Requests, but I'll put it here for now.