The information concerning this on the webpage states this:
" One important thing to note is that on the Mac a Scrivener project will appear to be a file with a “.scriv” extension, while on Windows, it will appear to be a folder with a “.scriv” extension. It is actually a folder on both systems, but the Mac’s operating system hides the internal contents of the folder to keep them safe. When viewed on Windows, this ‘file’ is shown for what it really is: a folder. If you navigate into this project folder you will find the binder file, which is a file with a Scrivener icon and a “.scrivx” extension. This file is an index to the other parts of the project, and it is the file that is used to open the project on Windows."
There is no binder file with a .scrivx extension when I transfer from Mac OS to Windows 10. There’s a binder.autosave and binder.backup. There is a Scrivener file though. If I right click ans select “open” Scrivener launches and my project file opens. Here’s the weird part. If I open Scrivener in Windows 10