This might be a related problem. Now the machine in question returns this error:
I'm sorry, but an uncaught exception occurred.
While parsing D:\User\renpy-6.16.1-sdk\xxx/game/bgm.rpy.
UnicodeDecodeError: 'utf8' codec can't decode byte 0xf9 in position 8: invalid start byte
Also, Editra refuses to open the script files, saying the correct encoding could not be determined. It asks me to choose an encoding but nothing works. In Scite, the code show up as gibberish like below.
Everything works fine on the main machine used to code our game.