Error messages

MSSQL: warning: database 'tempdb' on DEFAULT server instance explicitly included but believed to be non-backupable, will try anyway
MSSQL: error: can't get configuration for backup of database 'tempdb' on DEFAULT server instance: GetConfiguration timed out after 300000ms
MSSQL: backup of database 'tempdb' on DEFAULT server instance failed
MSSQL: warning: database 'Resource' on DEFAULT server instance explicitly included but believed to be non-backupable, will try anyway
MSSQL: error: can't get configuration for backup of database 'Resource' on DEFAULT server instance: GetConfiguration timed out after 300000ms
MSSQL: backup of database 'Resource' on DEFAULT server instance failed

Error description

System tempdb database backup is not supported, see Microsoft Docs.

System Resource database backup is not supported, see Microsoft Docs.

Steps to resolve

Exclude tempdb and Resource databases from SQL database backup list(s) in RVXConfig.