uh... I never seen this happening before in any renpy game. I think perhaps a file got corrupted while downloading it, have you trying to download and install the game again?
Try, nothing. I tried on Sinfull Valley & Crossworls. And the same!
Are you on Mac? Maybe you are missing fonts
Win 10 Enterprise LTSC
Uh... Then I really have no clue what it can be, I also use Win 10. I can only assume is a renpy thing, and maybe missing a font for some reason