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exFAT Formatted External USB Drive Not Mounting in Mavericks

I have an external USB drive (WD MyBook). It was formatted to the exFAT filesystem under OS 10.8. The drive is not readable on my Mac since I've upgraded to Mavericks. Disk Utility shows the volume, but cannot mount the exFAT partition. Disk Repair returns an error to indicate that the drive is faulty. I can still mount this drive on any machine that is not running Mavericks.

Best Answered by

Connie Yang

Answered on Tuesday, August 27, 2024

Since you say that your exFAT USB drive is readable on a Mac that is not running Mavericks and this issue appears after you've upgraded to Mavericks, I doubt that the exFAT formatted external drive not mounting problem is due to Mavericks bugs.

You can try updating your Mac if any minor updates are available. If it is not caused by the system errors, you have no choice but to reformat your drive. However, reformatting a drive will erase all data on it, you can use iBoysoft Data Recovery for Mac to get off files from your unreadable drive.

You need to contact support@iboysoft.com to get the version that supports OS X 10.9 Mavericks as the released official version supports macOS 14 - Mac OS X 10.11.