Windows 10 Home 8 gigs RAM
Cannot open the CR download file
You’re having the same problem is in this thread: Can't download upgrade or install - #4 by blockhead
.crdownload is the extension Chrome uses for partially downloaded files. The file you’re trying to open doesn’t contain the entire Windows installer for Vassal, because Chrome didn’t download it completely.
Try downloading the 3.7.7 installer again.