Thank you for letting me know.
After checking the game’s screens.rpy file, I’ve identified the problem— The text box image’s file name in a screens.rpy script does not match the one given in the game’s gui folders, causing the game to look for an image that technically is not there.
As I am currently away, I won’t be able to push out a patch immediately, but when I am able, I’ll do so ASAP.