Hard Drive 'read-only' Error on Mac

Seeing the 'read-only' error when trying to open an external hard drive, USB stick, or another type of storage on your mac may be an annoying issue. It will prevent you from accessing or copying files, and you might be clueless what to do in order to solve it. Thankfully, there are some pretty neat and easy ways to solve the hard drive 'read-only' error on Mac.

What is the Cause of the Problem?

Typically, there are two reasons why you might encounter this error message. The usual problem is that your disk is not using a file system compatible with Mac – for example, the majority of removable storage devices use the NTFS format. Another reason for the problem might be an issue with your Mac's user account permissions.

Fixing the Disk Drive Format

To do this, you will need to reformat the drive completely. Go to Applications -> Utilities -> Disk Utility. Find the external disk you want to work with, and then navigate to the Erase tab. Type the new name of the drive, and select the file system MacOS Extended (Journaled.) Finally, click Erase and wait for the process to finish. A similar method is used to fix 'The following disk images couldn't be opened' Error.

Fixing User Permissions

If your user account has insufficient permissions to work with the drive, then you will need to resolve this issue by going to Applications -> Finder. Then, press the key combination Command + I to open the Get Info window. There, select the Sharing & Permissions -> Privilege option to grant your user account permissions to Read & Write.

Repair the Disk

If both of these methods do not work, then you might want to try repairing the disk as a last resort. Go to Applications -> Utilities -> Disk Utility and find the disk you want to work with. Then, press First Aid -> Run to start the repair process.