Usually, the source of the error is a particular boot drive which is modified or corrupted. There are several reasons why users cannot complete the necessary tasks because of this error. When a device cannot erase or partition the drive, users are delivered one of these error messages:ĭisk Erase failed with the error: Couldn’t unmount disk. “Couldn’t Unmount Disk” error is an error message that might pop up on your Mac’s screen when the device is not allowed to repair particular permissions or directories in Disk Utility, for instance when trying to repair a hard drive. 'Couldn’t Unmount Disk” is the error message that appears on the Mac operating system.
Lost or corrupted data on the hard drive.Inability to open particular files or programs.However, it can still fail to fix some of them or even deliver error messages like “Couldn’t Unmount Disk” error.ĭue to the “Couldn’t Unmount Disk” error users might encounter these problems as well: Disk Utility is an important feature that helps to solve problems on the system. “Couldn’t Unmount Disk” is the error that, in most cases, appear when users try to format internal disk by Disk Utility or repair it on the Mac device. To repair damaged system, you have to purchase the licensed version of Mac Washing Machine X9 Mac Washing Machine X9.