It seems as if the backup is actually running but fails right at the end where snapshot info needs to be cleaned up. Snapshot info is written on the master server as well as the client.
You need to ensure that comms between client and master server is fine at all times - port connectivity as well as forward and reverse name lookup.
Check in client's bpfis log for comms issues with master.
Host Properties -> Master -> Client Attributes:
Add/select this client name
In Windows Open File Backup tab, under Snapshot error control, select 'Disable Snapshot and continue'.
My own experience with status 156 :
The cleanup error is that the "bpfis delete" operation could not find the snapshot "state file." That is typically a secondary failure after the original "bpfis create" operation failed. I think that's the case here.
The first failure in your job details screenshot shows a failure to read a pdf file from the snapshot.
Whenever you see "Error bpbbrm ... from client" in the job details, look in the client logs for a reason. You will find the failure to read the pdf file in the bpbkar log. However, error 156 (snapshot failure) comes from bpfis, so look in the bpfis log for the root cause. For Windows snapshots, you will find a pair of processes, one for a "bpfis create" command and one for the "bpfis delete" cleanup command.
For a Windows NT policy, bpbkar32 executes the bpfis create command.
Bpbkar32 not being able to read from the snapshot, bpfis delete not being able to find the state file, and status 156 all indicate that bpfis was not able to create the snapshot.
Check the bpfis log. Find the 156 error. Look upstream from there for the actual error(s).
Other troubleshooting: Can you create a snapshot outside of NetBackup using vssadmin? Can you mount the snapshot and read files from it?