If you used non-English version Win 10 as I do, change the game folder location to the root (c: or d: ). I solved the same problem by doing so.
Viewing post in If On A Winter's Night, Four Travelers comments
This could very well be the cause, thanks for pointing it out! But it doesn't have to be necessarily the root, any folder with English-only characters will work. The latest beta of the engine is in development right now and will probably do away with this restriction at last, but I have no idea when it will be stable enough for release. Hopefully soon!