Error when recover NMC database

When I ran the recoverpsm command to recover the NMC database, I got the error like this:
19221:recoverpsm: Restoring database lgto_gst
24037:recoverpsm: The file C:\\Program Files\\Legato\\Management\\lgto_gstdb\\lg
to_gst.db already exists, please remove the file or use the -f option before pro
ceeding
42137:recover: Restoring database credential file
6469:recover: C:\Program Files\Legato\Management\lgto_gstdb\gstd_db.conf not in
index
Nothing to recover
42138:recover: ============Warning================
42139:recover: Failed to recover credential file C:\Program Files\Legato\Managem
ent\lgto_gstdb\gstd_db.conf
42140:recover: You can also use recover binary to recover this file.
42141:recover: If this product's database directory path has changed since last
backup,
42142:recover: please update the path of the file to be recovered accordingly.

I want to know why recover the gstd_db.conf failed while I can find the file in the backup volume.