Restore of State Service Proxy of SharePoint Server 2010 fails with connection to the restore target has been lost.
This issue has been fixed in Backup Exec 2010 R2 Hotfix 148347
Please note that restore of a Application Service Proxy is not required. When performing restore of a Service Application, related proxy is created automatically. Symantec does not recommend to restore Application Service Proxies themselves.
Symantec Backup Exec 2010 R2
Symantec Backup Exec Agent for Microsoft SharePoint
Microsoft SharePoint Server 2010