There are 2 obvious issues ...

  -  You obviously do not have the proper privileges according to these 
messages:
9714:nsrinfo: cannot start session with server benamsubck1
39078:nsrinfo: File index error: permission denied, `bckossbe' on `benamsubck1' 
must have the 'Operate NetWorker' privilege. 

  -  Is this a NDMP backup media?
     At least the volume name "NAS203" indicates this.
     If so, you will not be able to scan the volume and retrieve the file index 
info (scanner -i) - only 'scanner -m' can be successful. This would be due to 
the NDMP format which does not have the emdedded CFI information.

My suggestion is to recover the backup to a temp directory using save set 
recovery copy the files from here.

+----------------------------------------------------------------------
|This was sent by carsten_reinfeld AT avus-cr DOT de via Backup Central.
|Forward SPAM to abuse AT backupcentral DOT com.
+----------------------------------------------------------------------

To sign off this list, send email to listserv AT listserv.temple DOT edu and 
type "signoff networker" in the body of the email. Please write to 
networker-request AT listserv.temple DOT edu if you have any problems with this 
list. You can access the archives at 
http://listserv.temple.edu/archives/networker.html or
via RSS at http://listserv.temple.edu/cgi-bin/wa?RSS&L=NETWORKER