Error is displayed whne i try to see backups in zimbra admin console

[isacap18]

Hi,
Every time I try to check zimbra backups this error is displayed:
"Server error encountered
Message: system failure: Error accessing backup target: unable to retrieve lastest session-account, account name=id maps Error code: service.FAILURE Method: BackupQueryRequest Details:soap:Receiver"

If i try to do a new backup this other error is displayed too:
"Server error encountered
Message: system failure: unable to retrieve lastest session-account, account name=id maps Error code: service.FAILURE Method: BackupQueryRequest Details:soap:Receive"

I checked and i have enough drive space and the lastest backup are in "/opt/zimbra/backup/" this error start to be displayed one week ago...so please help me

[threeta]

any luck fixing this error? can you post the fix please. thanx