Whenever DMG is damaged then you can’t mount dmg and therefore you required adequate approach for fixing the same issue. As a matter of fact DMG disk image is often utilized by Mac for proper functioning of the system. Even if it is a disk image but works as real volume which usually mounted as volume in Finder. But meanwhile you experience can’t mount dmg which disrupts the accessing of Mac system. Moreover your system fails to boot that’s why it is extremely necessary to overcome from this type of catastrophe as early as you can. Move to resolving part and through following below mentioned measures you can do so.
- First of all detect the DMG file which needs to be mounted.
- Then double click on DMG file to mount it.
- Unmount DMG file or click at mounted drive to eject.
- Then use repairing option of disk utility.
Hopefully this way you fix can’t mount dmg issue. But if the problem still then reformatting and re-installing OS X from the original disk is the mere choice. In data loss emerging scenario one should go opting Mac Data Recovery Software which is the smart and efficient way of getting lost Mac data back.