Snippet from the Backup Exec Install log; BKUPINST22.HTM
V-225-205: ERROR -1: The database 'BEDB' cannot be opened because it is version 904. This server supports version 869 and earlier. A downgrade path is not supported. Could not open new database 'BEDB'. CREATE DATABASE is aborted. ***To search for information about this error, click here
FATAL ERROR: BEMSI;BEOps.dll;BEOperations.cpp;:-1:BE_AttachDB() - SQL_AttachDB - The database 'BEDB' cannot be opened because it is version 904. This server supports version 869 and earlier. A downgrade path is not supported. Could not open new database 'BEDB'. CREAT
V-225-118: Error installing BEDB ***To search for information about this error.
The SQL Instance currently hosting the Backup Exec Database (BEDB), is a higher SQL version than the SQL Express 2017 Instance that Backup Exec 22 installs. The BEDB cannot be attached to an SQL instance that is lower than the DB version.
With effect from Backup Exec version 22, Backup Exec uses an SQL Express 2017 64-bit edition (exact version is 14.0.1000.169) instance to host the BEDB.
That default instance is now called BKUPEXEC64.
During the upgrade of Backup Exec from an older versions (20.x - 21.x) to version 22.x, it detaches the Backup Exec Database (BEDB) from the old SQL instance and attempts to attach it to the new SQL 2017 Express BKUPEXEC64 Instance, that is created during the Backup Exec 22 upgrade process.
If the Backup Exec 20.x/ Backup Exec 21.x BEDB is currently hosted in a custom SQL Instance which is a higher SQL version than SQL Express 2017 Instance used by Backup Exec 22, the upgrade will fail.
To ensure that the Upgrade of Backup Exec completes successfully to the latest version, one of the following solutions should be performed.
SOLUTION 1:
1. Create a new SQL Instance by the name of BACKUPEXEC22 using the SQL version that is currently hosting the Backup Exec Database (BEDB) in BE 20.x/ BE 21/x as per the article.
How to manually install a named instance of SQLExpress for Backup Exec (veritas.com)
2. Install SQL Server Management Studio on the server, if not already installed and provide the necessary DB permissions for the Backup Exec Logon Account to the new BACKUPEXEC22 SQL Instance created.
3. Navigate to the Backup Exec Installation Directory in File Explorer and launch BEUTILITY.
4. Select the option to move the Backup Exec Database Instance from the existing SQL Instance to the newly created instance BACKUPEXEC22 as per the article
How to change the Backup Exec database location to a new instance using BEUtility (veritas.com)
5. Once the Backup Exec Database is moved to the new SQL Instance (BACKUPEXEC22), ensure that the following Registry entries are updated to the new SQL Instance.


6. Perform the upgrade of Backup Exec from the older version to Backup Exec 22. The Backup Exec Database will remain attached to the BACKUPEXEC22 instance.
7. Once the upgrade has completed successfully, you may uninstall the old SQL Instance if required, along with the SQL 2017 Instance created by Backup Exec, from the Server.
SOLUTION 2:
Once the initial upgrade of Backup Exec to version 22 rolls back, two SQL Instances will be present on the server. The SQL 2017 Express Instance created by Backup Exec (BKUPEXEC64) during the upgrade process and the SQL Instance that is currently hosting the existing Backup Exec Database (BEDB).
1. Upgrade the SQL 2017 Instance (BKUPEXEC64) created by Backup Exec during the BE 22 upgrade process, to the same version of SQL used by the Instance currently hosting the Backup Exec Database (BEDB).
2. Use BEUTILITY and move the Backup Exec Database Location from the existing SQL Instance, to the upgraded BKUPEXEC64 SQL Instance as discussed in article;
How to change the Backup Exec database location to a new instance using BEUtility
3. Confirm that the Registry entries are pointing to the correct SQL instance BKUPEXEC64.
4. Perform the upgrade of Backup Exec from the older version to the latest version of Backup Exec 22.
5. Once the upgrade is completes successfully, uninstall the old SQL Instance if required from the Server.
Note: Please ensure that the current SQL Instance version hosting Backup Exec Database (BEDB) is higher than the SQL Instance version used by Backup Exec during Upgrade.