FIXING External USB Harddrive Problem on Mac (DiskManagement disenter error 0) exFat
This video explains how to fix a problem with external hard drives, which were accidentally unplugged from a Mac Computer while they were still in use.
The problem manifests itself in a way that the drive is not mounting anymore.
The. fix shown in this video is connect the hard drive to a Windows computer, where a scan and repair procedure is suggested. After running this procedure the external hard drive will mount again properly on any Mac.