I received a similar issue today when doing a simple export / import of a windows 7 vm running Oracle VM 4.3.1 on linux mint. I exported in OVF 2.0 and it generated an .ova file. I had nearly identical error message when importing the image. I am assuming the image was made with Oracle VM.
"Failed to import appliance /home/val/Desktop/win7.ova"... "the OVF describes no such image"
THE FIX: All I had to do was rename the .ova file to .ovf; you may have to change the .ovf extension to .ova as well. Also ensure you are the owner of the file (chown) and you have correct permissions(chmod). This worked for me it may work for you.
I found this fix here: https://www.virtualbox.org/ticket/9414