Subject Cannot restore 32GB DB - fails at end, unusable. Any ideas please.

gbak:    activating and creating deferred index K_MERCURY_EMAIL 

gbak:cannot commit index K_MERCURY_EMAIL 

gbak: ERROR:operating system directive CreateFile failed 

gbak: ERROR:    The system cannot find the path specified.  

Database restore canceled 21:17:19 due to IBPP exception:

*** IBPP::SQLException ***

Context: ServiceImpl::Wait

Message: isc_service_query failed

SQL Message : -901

Unsuccessful execution caused by system error that does not preclude successful execution of subsequent statements

Engine Code    : 335544342

Engine Message :

action cancelled by trigger (3) to preserve data integrity

Cannot deactivate index used by a PRIMARY/UNIQUE constraint