Hi! Thanks for checking out the game. I am at a loss here. I just downloaded a fresh copy from itch and it started up fine (I use Win10 as well). The only thing I can think is that something was corrupted in download although I have never seen that before but maybe try a fresh copy from download. Also, the data/quest files are not interchangeable between the two (just in case you tried that?). Any more info on the error? Thanks and sorry for the frustration. :(