Backup Exec 20.x and 16 are affected by the following issue: "Backup Exec console crashes after installing .NET Framework 4.8" https://www.veritas.com/support/en_US/article.100045500.html.
Veritas recommends, where possible, to upgrade to the latest available version of Backup Exec. To aid customers with upgrading, the following resources can be used:
Please use this thread for any questions on this issue with .NET 4.8.
Fixed! I uninstalled .NET 4.8 and installed .NET 4.0. (Don't have the install disk handy) And the backups were running all the time the console was crashed.