Backup job fails with the stated error. Failures are intermittent on different tasks.
Backup Exec is installed on the same server as vRanger. They are sharing the SQLexpress database, and in this case clearly this server is under resourced.
Do not share SQLexpress with Backup Exec or any other software product. Move one of the databases to an external SQL server, as long as it is not the vRanger Catalog SQL service.