Elsewhere I found out that Microsoft has changed their NTFS: it changed from LFS (Log File Service) 1.0 to LFS 2.0, which to Linux is an „unknown filesystem“. As far as I understand it, once you have made the Windows 10 update, you can not revert to LFS 1.0. This will and already has caused some issues to some Linux users with dual booting. They find that the Linux partitioner and some installers hang if you have this type of W10 NTFS partition, at least this appears to be true in OpenSUSE, as yet I'm not sure if others are affected.
Just another thing Microsoft is doing which makes life difficult....
Stuart