Delete and reinstall! Have you tried this? also make sure you copied it exactly. No mistakes, no accident Capital letter,
Nothing.
Make sure you're using a standard English (US) keyboard layout some layouts (like AZERTY or others) might cause issues. Try Another PC (if possible) If it works fine on another computer, then the issue is definitely something with your system settings. Uhm, that's all I can come up with. Sorry! If it still doesn't work I suggest somehow getting the developer's attention? Sorry I can't be more of help.