Hello rugbyjack2005,
Did you check the drive Permission Settings of My Book?
If not, try to check after changing the permission for My Book in Read & Write which might help to resolve this issue. You may follow the below steps to change the drive permissions:
- Select a disk, then choose File > Get Info.
- If the information in Sharing & Permissions isn’t visible, click the disclosure triangle.
- If necessary, click the lock icon to unlock it, then enter an administrator name and password.
- Click a user or group in the Name column, then choose a privilege setting from the pop-up menu.
- Select Read & Write
Otherwise, you need to reformat the drive in compatible file format before taking the backup of important data.
