alright I have no idea what might be causing this, try this last thing, you said you has slkscre.ttf on your pc, maybe the file explorer automatically chose not to copy it again, so try copying slkscre.ttf to the game folder
if this doesn´t work all I can recommend you is to get the .exe version, you can still read the script, and it has a script on this non-source version as well, but only the .exe will run