To replace the corrupt partition map simply go to Disk Utility and erase the USB drive with Disk Utility.

You can only replace the partition map after recovering the data. You will require installing a data recovery software that can first recover files.ĭisk Utility or any other partition repair software can’t repair the partition map. Since the USB drive is unavailable for file transfer hence recovery of files via Command+C or drag-dropping files to another drive is impossible. However, if your USB is partitioned into multiple volumes, then each volume has a separate directory structure, but the partition map remains unique for all the volumes. Partition Map is the unique layout of the USB drive or any other storage disk. The above statement confirms the corruption of either partition map or directory structure.ĭifference between Partition Map & Directory Structure? Back up as many of your files as possible, reformat the drive and restore your backed-up files It could be one of these.ĭisk Utility can’t repair this disk. Watch the statement generated by Disk Utility.Wait for the Disk Utility to process the USB drive corruption report.This partially visible USB drive can verify & repair via Disk Utility First-Aid on macOS Mojave, High Sierra, Sierra, El Capitan, Yosemite and below OS X. However, your USB will appear on the left panel of the Disk Utility though greyed out. Further, you won’t find your USB drive mounted or available on the left side of the Finder. Suppose your USB drive has a faulty partition map then the USB will not mount for reading or write operations. With a working partition map, your USB will always show up in the Finder or Desktop.īut, what if the Partition Map is Corrupt? The partition on macOS could be APFS, MacOS Journaled, Encrypted MacOS Journaled or Case-Sensitive. Your USB drive on macOS has a working partition map that makes the storage device available for data storage and transfer.

Disk utility erase process has failed