This error generally results from improper modification of the boot drive, such as partitioning, disk verification or repairing or formatting.
However, it still can fail to fix disk issues accompanied with some error messages, such as “Couldn’t Unmount Disk” error. This article will focus on this error and provide 5 feasible solutions.ĭisk Utility plays an extremely important and good role in solving disk problems on Mac system.
“Couldn’t Unmount Disk” error message usually pops up when you try formatting, partitioning, verifying or repairing internal disk by Disk Utility on Mac system.