This can happen with disks that are formatted as ntfs. The external hard drive shows up as 'read only' on mac, help hi there, do you know how to make the external hard drive accessible again when it shows as 'read only' on mac? An external drive that is read only on mac is a very common issue with proven solutions This article is all you need to fix it. When encountering a “mac external hard drive read only” error, common causes include ntfs formatting and permission settings
OPEN