If the error only occurs on a backup job performed by the AhsayOBM scheduler, please verify if the “Log on” account of the AhsayOBM scheduler service has sufficient permission to access the designated temporary directory:

1. Open [Control Panel] -> [Administrative Tools] -> [Services] -> [Online Backup Scheduler (Ahsay Online Backup Manager)] -> [Log on]
2. Select the [This Account] option
3. Enter the Login Credentials
4. Restart the [Online Backup Scheduler (Ahsay Online Backup Manager)] service

In the cases where AhsayOBM is not installed on the SQL server, please verify if the “Log on” account of the MS SQL Server (MSSQLSERVER) service has sufficient permission to access the designated temporary directory:

1. Open [Control Panel] -> [Administrative Tools] -> [Services] -> [SQL Server (MSSQLSERVER)] -> [Log on]
2. Select the [This Account] option
3. Enter the Login Credentials
4. Restart the [SQL Server (MSSQLSERVER)] service

from ahsay wiki