No problem!
I think, if I'm not wrong, there is only one .exe (in another version there was .exe 32, which in some pc could fail); just in case it is Mac?
Maybe something happened while downloading and the file is corrupted?
Even if it doesn't give you a warning message is the most disconcerting thing!
I hope that when I upload 0.5 there won't be any problem.
See you!