After upgrading to NVBU 10-11.x the default user is missing.
Some jobs will fail with the error, "Owning user does not have EXECUTE_JOB permission"
In the logs from the upgrade the following message can be found.
Auditor database migration ERROR: 1 out of a total of 6 users records failed migration.
Running the following report will show UNKNOWN USER
nvreport -class "defined jobs" -format "%title::55 %jobdefinitionid::5 %creatorid" -sort "%title"
This is fixed in NetVault Backup 12.0 and later.
If it is not possible to install the original version of NVBU, restore the NetVault Database and then upgrade to NetVault Backup 12.0 or higher, it is also possible to connect directly to the PostgreSQL database and manually add the default user with uid 0 to the users tabel in the netvault_auditing database.