Grant full Exchange access permissions at the Organization Management level. It is recommended that the backup user account have full Exchange permissions on the Exchange Server to perform backup and restore operations.

Permissions are then propagated automatically to any new Exchange Servers that you add under the level at which the permissions are assigned.

You must have Exchange administrative permissions to grant permissions to other accounts.

To grant full permissions for Microsoft Exchange 2010/2013, use an account with the Organization Management role.

https://support.digitalwest.net/KB/a314/how-can-i-turn-off-circular-logging-in-exchange-20032007.aspx

Set-StorageGroup -Identity "First Storage Group" -CircularLoggingEnabled $false

Get-MailboxDatabase

Set-MailboxDatabase -Identity "Database Name" -CircularLoggingEnabled $false

Get-PublicFolderDatabase

Set-PublicFolderDatabase -Identity "Public Folders" -CircularLoggingEnabled $false