For Veeam Plug-in 11a, the backup files upgrade is not obligatory. However, backup files created by Veeam Plug-in 10 will not be supported in the next version.
To disable the warning regarding upgrading Enterprise Plug-in backup data, create the following registry value on the Veeam Backup & Replication server.
Key Location: HKLM\SOFTWARE\Veeam\Veeam Backup and Replication
Value Name: DbPluginBackupUpgradeWarnings
Value Type: DWORD (32-bit) Value
Value Data: 0
Value Data options:
0 - Disable warning system.
1 - Enable warning system.