MICROSOFT MADE A FILESYSTEM NTFS NECESSARY FOR WORKING WITH ONEDRIVE
Perhaps, it has passed unnoticed for most of users, but Microsoft company made changes to the OneDrive cloud. So any user can't do data's backup from filesystems, except NTFS.
If hard drives of your computer uses other filesystem, there is no way to download files to the OneDrive cloud. The reasons of such decision in Microsoft haven't comments. Also it's not known, when this change entered into force. First messages about it was on 1'st July on forums.
If user with unsupported filesystem tries to copy file in OneDrive, he would get an error. An error means, that user should to format drive and install filesystem NTFS or use other drive.
Of course, such change doesn't please many users. It is bad, that it happend quietly and without warns from Microsoft's side, on whose software enterprises work, not only personal computers.
Microsoft will force to make an official claim, in present moment there is no detour for using Drive without NTFS.
I imagine that won't take too long though... Don't underestimate a hacker who really wants something!