Keep getting these messages:
Time Machine couldn’t complete the backup to “My Passport Air”.
Files can’t be copied onto the backup disk because it is read-only. You may need to repair or erase the disk using Disk Utility. If the disk can’t be repaired, select a different disk for backups.
Latest successful backup: 25 September 2018
macOS can’t repair the disk “My Passport Air”
You can still open or copy files on the dis, but you can’t save the changes to files on the disk. Back up the disk and reformat it as soon as you can.
BUT I can’t access it. What dop I do?