Within the NB Admin Console, in the client tab of that policy, is the correct corresponding "Hardware and operating system" being chosen?

What's the NB patch level on server & client?

Did you ever find a fix for this.  I recently had the same thing happen.  I am running NBU 6.5.4

Create log folder <NetBackup_path>\logs\bpbkar  on client, try to perform backup and check log file in this folder. may be somthing like this:
seer.entsupport.symantec.com/docs/305254.htm

ensure that the policy type is still MS-Windows-NT  (sometimes people accidently change it to styandard)

remove TIR

any special characters in the policyname?

can you publish the output of bppllist $POLICYNAME -U
 

 HI Joseph
as you said that you are using ALL_LOCAL_DRIVES directive. in the drives you also have any network drive ?
if yes 
than try this
- create a specific account for Netbackup onto your domain,
- put this account in the local administrators group of your Netbackup machine,
- run the Netbackup service with this account (instead of Local System Account)
- put rights for this account on the share you want to backup.

Note:-