This means older file systems, such as FAT32 and exFAT, and newer ones, such as ReFS, will now provoke an error message when OneDrive starts up.

Files will have to be stored on an NTFS volume to keep using the software. While FAT disks can be converted, ReFS volumes must be reformatted and wiped.

This has left various OneDrive users rather unhappy. To be fair NTFS is Window’s default file system and most Windows users will not care or notice.

But people using SD cards to extend the storage on small laptops and tablets will typically use exFAT. Those using Storage Spaces to manage large, redundant storage volumes will often use ReFS.

Microsoft said that a warning message should have existed but was missing when a user attempted to store their OneDrive folder on a non-NTFS filesystem. Now, this has been fixed.

But Microsoft wanted OneDrive always to have warned about these usage scenarios and that it's only a bug or an oversight that allowed non-NTFS volumes to work in the first place.