A Microsoft file hosting and synchronization service.
Check to see what partition format your Mac drive has. I had they problem since my drive was APFS case-sensitive format. Go to disk utility . Disk Utility menu-> EDIT->Add APFS volume. Select the APFS as format not the APFS case sensitive. This will create a second volume without deleting the current volume. This creates a MOUNT point. Then setup Onedrive in the new volume....This worked for me.