Virtualbox problem

[faustf]

hi guys i have a big problem with some virtualbox machine
i have 10 machine 4 machine have this problem

Document is empty.
Location: '/media/stefano/BACKUP/macchine virtuali/NewSviluppoAutoit3__4/NewSviluppoAutoit3__4.vbox', line 1 (0), column 1.
/home/vbox/vbox-5.0.2/src/VBox/Main/src-server/MachineImpl.cpp[736] (nsresult Machine::i_registeredInit()).
Codice 'uscita:
NS_ERROR_FAILURE (0x80004005)
Componente:
MachineWrap
Interfaccia:
IMachine {f30138d4-e5ea-4b3a-8858-a059de4c93fd}

someone can help me???
thankz at all for support

[soky]

This location is not removable media?

[Cosmo.]

Strange. This would indicate, that your username on the host is "vbox". Nothing is impossible, but this is more than unlikely.

/home/vbox/vbox-5.0.2/src/VBox/Main/src-server/MachineImpl.cpp[736] (nsresult Machine::i_registeredInit()).

And why does the VM gets used from a backup place and not from the place as set in the VB manager?