How to solve the issue of VirtualBox showing a VM with UNMOUNTABLE_BOOT_VOLUME?

I want to provide some insight as to what might be the case with UNMOUNTABLE_BOOT_VOLUME.

With those .zip files provided, if you use Mac's default zip program to unzip it (by just double clicking on the zip file on OS X El Capitan), then it will first create a .ova file, and then it will immediately uncompress again, to 2 files: one .vmdk file and one .ovf.

Now, you cannot use those .vmdk files as is. You have to double click on .ovf for it to be opened by VirtualBox, and then it will clone the .vmdk image and make it into a VM.

I think you can also use something like the 3rd party Unarchiver, and unzip it, and it will create a .ova file from the .zip file. In this case, also just double click it for VirtualBox to use it, and I think in this case it also would not have the UNMOUNTABLE_BOOT_VOLUME problem.

Same problem, this work for me:

When you have .ovf file from VMWare, open it with any text/xml editor, and

1. replace word ElementName with word Caption in the whole file

2. replace vmware.sata.ahci with AHCI

Save and import to VirtualBox (doble click in ovf file)