VMware OS had Password Encryption and After Converting to VDI , it Gives Fatal Error

VMware OS had Password Encryption and After Converting to VDI , it Gives
Fatal Error

I had Ubuntu installed in vmware [Host OS = Windows 8], now I have removed
windows 8 and am in Ubuntu as Host OS and have Virtual Box.
I did conversion from vmdk to vdi, but now, while accessing VDI it gives
Fatal Error, as No Bootable media found, it doesn't even ask password.
Is there any way, i can login to my VM Ubuntu machine via virtualbox. It
has lots of my business confidential data and i don't want to loose them.
Thanks