none of the requested files were backed up (2)

Hello,

can any one explain me this error :

 Info bphdb(pid=5652) Backup started           
5/10/2016 11:59:39 AM - Error bpbrm(pid=9056) from client tcimor-db1: ERR - command failed: none of the requested files were backed up (2)
5/10/2016 11:59:39 AM - Error bpbrm(pid=9056) from client tcimor-db1: ERR - bphdb exit status = 2: none of the requested files were backed up
5/10/2016 11:59:39 AM - Info bphdb(pid=5652) done. status: 2: none of the requested files were backed up  
5/10/2016 11:59:39 AM - end writing
none of the requested files were backed up(2)

i need solution for this

best regards