Facing External drive partition suddenly cannot mount error? It is a conman a search term for many Mac users? Partitioning the hard drive enables the users store and manage data accordingly. But any kind of interruption while partitioning can turn nasty and causes various irritating issues on Mac system. Improper partitioning of Macintosh hard drive can results in various problem of users including external drive partition suddenly cannot mount issue, data inaccessibility, and so on. Since it is a very critical issue thus it would be sensible fix it immediately without any further delay. In order to resolve this problem you may try Disk Utility or FSCK command, but as it is directly related partitioning problem hence the best option to fix external drive partition suddenly cannot mount issue is to repartition your Mac system. In such situation you will have to format your entire Mac drive then create recreate new partitions carefully. While doing so this very issue will definitely get resolved but it would also be responsible for loss of your all important files. But external drive partition suddenly cannot mount get fixed once then your files can easily be recovered with the help of Mac Data Recovery Software.