The following error appears in the AccountServer error log:
Error: Error when calling the RestoreDatabase method on net.tcp://0.0.0.0:50148/sys/transfer: Cannot open backup device 'C:\ProgramData\Attix5 Pro\AS_Service\ServerBackups\Restore\AS_Service\ServerBackups\BackupServer.bak'. Operating system error 5(error not found).
RESTORE DATABASE is terminating abnormally.
Changed database context to 'master'.
This error gets reported from your Slave AccountServer and is usually caused if you MSSQL server service account does not have sufficient rights to the AS_Service\ServerBackups folder. In most cases your MSSQL service runs under the NETWORKSERVICE built in user account that does not have rights on the disk.
Give the user account that your MSSQL service runs under Read rights to the AS_Service\ServerBackups >folder and subfolders.