The error "macOS can't repair the disk 'Seagate'. You can still open or copy files on the disk, but you can't save changes to files on the disk. Back up the disk and reformat it as soon as you can." is likely caused by disk corruption, a broken USB port or cable, or software issues.
While you still can copy files on the drive, it's highly recommended to back up the important data to another storage device to avoid data loss, as your drive may get worse the more you use it.
For those who can't access their drives, they will need to recover the lost data using a data recovery software. From my experience, the best data recovery tool for macOS is iBoysoft Data Recovery for Mac. It allows you to restore lost data from corrupted or inaccessible drives and provides support for major file systems, such as APFS, HFS, HFSX, Mac OS Extended , FAT32, and exFAT.
Besides, it's compatible with macOS 13 Ventura ~ Mac OS X 10.11 El Capitan. You can get it from the button below to preview your data for free.
Once your data is secured, you can go ahead to fix the drive. Try the following basic troubleshooting tips first:
- Safely eject your drive and reconnect it using a different USB cable or port.
- Reboot your Mac and retry using the drive.
- Run First Aid in Recovery Mode to repair your Seagate drive.
- Run FSCK in single-user mode to fix your drive.
If the issue persists, the last option is to reformat your drive. Just keep in mind that this will erase all data on it, so make sure you have backed the important files up beforehand.