Hi,
Are you getting this error during test run?
This error usually occurs when The backup device specified in the backup job is a "backup-to-disk-folder" that has not been written to before.
Just try running a small overwrite backup job on the backup to disk folder and check the results.
Once the backup to disk folder is been overwritten for the first time then you will be able to "Test Run" on it, there after.
Additionally refer the following technote:
http://seer.support.veritas.com/docs/265015.htm
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